Pyramids

Built as gargantuan tombs of shining white limestone, the pyramids were designed to hide dark secrets of the dead for eternity. For thousands of years, they have prompted fantastic myths and legends, as well as real and baffling scientific riddles. How were these mausoleums constructed, hundreds of feet high, true to within inches? Why was a nation devoted to housing its dead? Who were the men who hauled billions of tons of stone? Now, science is beating down the pyramids' defenses, shattering ancient myths, and revealing the truth. The pyramids of ancient Egypt stand like giant sentinels watching over the city of Cairo. Built more than 2,000 years before the birth of Christ, these stone giants continue to mystify and captivate archaeologists seeking to understand their origins and purpose. I think Egypt has such a grip on us because they had access to stone. And with that stone, they built the world's first skyscrapers. There's something about us that we see in that. The pyramid builders left no record of how they erected these massive superstructures. And thousands of years of myth and legend have hidden their real purpose. The only clues are the pyramids themselves. Scientists must study the stones to discover how these extraordinary buildings were constructed and to learn who built them using simple, primitive technologies. These are very sophisticated monuments. The Great Pyramid is the high tech of antiquity. The scale of the achievement is astonishing. The Great Pyramid is 481 feet tall and is made up of 2.3 million blocks, some weighing as much as 50 tons. The whole structure weighs almost 6 million tons. That's the equivalent of 16 Empire State Buildings. For 38 centuries, it was the tallest building on Earth. What's more, it's an incredibly precise piece of engineering. The 755 foot sides vary in length by less than 2 inches. It's not just the exterior building that's extraordinary. Inside is a complex of passageways and chambers built from one of nature's hardest rocks. The stonework is so precise that even a credit card cannot slip between the blocks, all constructed by a people who hadn't discovered the wheel. The accuracy of the Great Pyramid is something that makes me stand in awe. The first Egyptologists tried to blast their way to the truth with dynamite. They forced their way into the pyramid's secret chambers, but they may have destroyed more than they uncovered. Dynamite especially might have obliterated clues left behind by the ancient Egyptians, telling us more about the pyramids or how they were built. Now archaeologists are using the latest technology to search for wonders hidden deep within the stones. I really actually believe that the burial chamber of that king is still hidden inside the pyramid. But for other archaeologists, it's the buildings themselves that are the true wonder. The greatest mystery about the pyramids is not secret chambers. It's how the Egyptians managed to build them with the technology they had. The ancient Egyptians didn't master pyramid building in one leap. It took long years of trial and error and one near disaster for them to evolve from building simple mud constructions to the Great Pyramid at Giza. The first pyramids were built on the west bank of the River Nile around 2,600 BCE. The earliest design was the Step Pyramid at Saqqara, possibly the oldest stone building on Earth. Rising 204 feet from the desert sands, this was a breakthrough in the history of construction. It didn't have smooth sloping sides, but instead rose in a series of levels or steps. The first flat-sided true pyramids were built 60 years later by the pharaoh Sneferu. His son Khufu built the Great Pyramid, the first and largest of the three pyramids at Giza. And then a series of smaller, highly decorated pyramids were built at Saqqara. How the Egyptians built these giant superstructures using the simple technology of the time is an ancient mystery. The first challenge was to survey the site and mark out the pyramid in the correct alignment. They chose the site with care to ensure that the bedrock was capable of supporting many millions of tons of limestone. The ancient architects then marked out the building so that each side was aligned to the points of the compass, north, south, east, and west. Today, we would use digital compasses and laser sighting equipment. But the ancient Egyptians had none of this technology. Instead, some experts think they looked to the skies. By observing where the polar stars rise and set, it's possible to calculate true north. First, the architects built a semicircular wall to act as a flat horizon. On this wall, they could mark the rising and setting points of a particular star as it rotated around north in the night sky. A line drawn exactly midway between these marks would point due north. Using just this low-tech method, the Great Pyramid was aligned with breathtaking accuracy. It is off true north by less than a 20th of a degree. Engineer and pyramid writer Robert Boval has aligned modern buildings himself. He is astounded by the accuracy achieved by the ancient Egyptians. It beats me how they did it. I've set out buildings with optical instruments with the aid of cranes to place the stones. And sometimes, I don't get them that accurate. Having calculated due north, the architects plotted out an alignment line that forms one side of the pyramid's footprint. They then marked out the remaining three sides using measuring rods and cords. With the plan of the pyramid now set, the engineers then carved a level base out of the bedrock to support the giant structure. A perfectly horizontal foundation was needed for a precise and stable pyramid. British engineer Dennis Stocks is an expert in ancient Egyptian construction techniques. His work has unraveled many of the mysteries of pyramid building. Modern foundations are leveled with lasers and spirit levels. Stocks believes that the Egyptians used water. In order to get the pyramid base nice and flat and level, the ancient Egyptians used a channel. It's like this one here, only it would stretch all the way along 755 feet, the whole side of the pyramid. And then they would put some water in. And it would act as a kind of spirit level. All he has to do is follow the line of the water along it, and then he can be sure that the pyramid base will be truly level and truly horizontal. Stocks believes that such a water trench could have been built on a massive scale along the whole edge of the pyramid. In this way, the engineers could ensure the whole base was level. But to check that all 2.3 million blocks were kept level as the pyramid grew upwards, the Egyptians used another ingenious device. The tool I'm using is made of wood, and it's called the A-frame. All it is is two pieces of wood joined together at 90 degrees at the top with a crossbar and a hanging plumb line. To calibrate it for use, it is placed on a flat surface of water. And then a line, which you can see there, is marked right behind the hanging plumb line. So that you know when you test it on a surface and the hanging plumb line coincides with the mark, we know that it is showing a truly horizontal flat surface. With the design laid out and the site level, construction could now begin. For this, the Egyptians needed stone, millions of tons of stone. But how did they quarry such incredible amounts without the aid of dynamite, jackhammers, or even iron tools? During the ancient Egyptian Old Kingdom, 18 major pyramids were completed in a 500-year period. They contain a third of a billion cubic feet of stone, stone that had to be quarried, cut, and transported to the sites. Even for modern engineering companies with modern technology, this would be a daunting task. Yet the ancient Egyptians managed it with the most rudimentary tools. Dennis Stocks is traveling to Tura, near Cairo, where much of the high-quality limestone used in the pyramids was quarried. He believes the Egyptians cut this stone using a soft metal, copper. Stocks has built replica copper chisels based on ancient artifacts found in Egypt. By using those, I feel that I am as close as I can get within the mind of ancient Egyptian workers and how they felt. But copper is a soft, malleable metal which bends and blunts easily. How can it be used to cut limestone? Now, the tools that I have in my hand at the moment are the first ones that the ancient craftsmen would use. And this one is a mallet, which is used to strike this copper tool, which is shaped into a chisel. And in order to do this, you lay the chisel against the stone at an angle, position the mallet, and then strike. Quite hard blows, and you will see big chips of stone coming away. That's all right for rough working, but we have another copper chisel, which can be used for more finer working in order to get much less stone off at a time, but will bring the surface closer towards a surface which is totally flat. Stock's research shows that it's possible to carve limestone blocks using soft copper chisels. And it turns out that the Egyptians were the unwitting recipients of some good fortune. Detailed chemical analysis of ancient tools shows that Egyptian copper wasn't pure. It contained small traces of arsenic. By a lucky chance, this impurity holds the copper crystals together and actually makes this copper tougher than its pure form. This fluke of chemistry helped the Egyptian stonemasons quarry most of the 2.3 million limestone blocks in the Great Pyramid. The pyramids are mostly made of the relatively soft rock limestone. But the Egyptians also used a much tougher kind of stone, granite. They used this hard, beautifully colored stone for the most important sections of the design, such as the king's chamber within the Great Pyramid. And copper chisels have absolutely no effect on this rock. Sophisticated modern quarrying tools can cut through granite, but the Egyptians had not even learned how to forge iron. Generations of archaeologists could not solve the puzzle of exactly how they cut these 50-ton granite blocks. But now, experimental archaeology is beginning to explain this technological mystery. Dennis Dox thinks he has the answer. He believes the Egyptians did use copper, copper saws, and not just ordinary saws. They didn't even have teeth. This material here is very hard granite. And to cut this, you need a special tool. And this is a copper saw. But it's toothless. It's got no teeth at all. And you say, well, what's going to do the cutting? Well, it's sand. But it's the quartz crystals within the sand which embed themselves into the softer copper. And because the saw's dragging those crystals backward and forth within the slot, that actually does the cutting. And slowly, bit by bit, the stone is cut right the way through. Quartz crystals in the sand are so hard that they gradually grind through the solid granite. But using these saws, the ancient Egyptians could only have cut granite at a rate of two cubic inches an hour. It still would have taken four months to carve out the sarcophagus inside the Great Pyramid. With soft copper and a cutting edge provided by arsenic and sand, the Egyptians cut vast quantities of rock. They had to then assemble these blocks into a monument that could stand the test of time. But what made the Egyptians decide to build a pyramid in the first place? Why did they choose this now iconic shape? They were looking for a stable form. Like a mound of gravel, the pyramid is supported by a wide base and low center of gravity. More than 2 thirds of the weight is in the bottom third of its height. But the design wasn't just about engineering. It was also influenced by their beliefs. When people want to go up, to do so and have stability, a mound is very stable. But of course, there is a symbology in all of this. There may be several mystical influences behind the pyramid shape. One explanation looks at the worship of a mystical stone known as the Benben stone. Nobody knows where this legendary stone originated. Some think it was a meteorite. It has long since vanished. But the pyramidions, or capstones, that form the very top of the pyramids are modeled on the original pyramid-shaped Benben stone. Could this be the reason why pyramids are built in their distinctive form? But with the sun playing such a key role in Egyptian religion at the time, there is another possibility. Maybe the sun itself was the key. The pyramid can be seen as a stone representation of a sun ray coming down from the heavens. When the sun emerges from behind clouds, the beam created can sometimes resemble a pyramid. So a stone representation of a sunbeam is a possibility. But perhaps it was simply the pure geometrical form of a pyramid that appealed to the Egyptians. Ironically, the first pyramid, the step pyramid, didn't have smooth sloping sides. It rose in six separate layers. It was Pharaoh Sneferu, the pioneer of pyramids, 60 years after the step pyramid was built, who created the first smooth-sided true pyramid. This was a radical new concept, and its success would rest on a critical engineering decision. At what angle should the sides rise? The steeper the angle, the taller and heavier the pyramid would be. If they made it too steep, it might be too heavy for the foundations. Sneferu's architects settled on an angle of 55 degrees. At first, things went well. But halfway through construction, cracks began to appear in the pyramid's internal chambers. According to a survey by Italian archaeologists Maragiolio and Rinaldi, the pyramid is built on soft, slaty clay. Only the edges rest on a solid stone foundation. As the pyramid rose, this soft core sank under the weight. The architects had to come up with an answer, or the pyramid might collapse. Construction stopped. Eventually, their dramatic solution changed the whole direction of the build. The architects decreased the angle of slope from 55 degrees to 43 degrees. This reduced the height of the pyramid by 100 feet and the weight by more than 400,000 tons. The engineers' mistake probably angered the pharaoh, but their solution was a success. 4,500 years later, the bent pyramid, as it's now known, still stands, though with its slightly unusual shape. Major pyramids would never again be built at such a steep angle. For his next pyramid, Sneferu's architects were understandably cautious. They built the Red Pyramid at just 45 degrees. It has the shallowest angle of any of the Egyptian pyramids, and it's still standing. It's the oldest true smooth-sided pyramid in Egypt today. After this success, the architects grew more confident. They now built steeper and steeper, culminating in the angle of the Great Pyramid. Its sides climb at an angle of slightly less than 52 degrees, rising to a summit of 480 feet. But how did they manage to maneuver 2 and 1 half ton blocks to such an incredible height without the crane or the block and tackle? It was a challenge to the ancient Egyptians and still remains a mystery to modern archaeologists. Egyptologist Mark Lehner has spent 30 years studying the pyramids hands-on. My approach to the question was, where are the quarries? What kind of a ramp can you get from the quarry to the pyramid in a functional slope? Lehner and almost all Egyptologists believe that some kind of ramp was used to raise the stone blocks. The type of ramp remains a mystery. Did they approach the pyramid straight on, zigzag up one side, or spiral around it? It's not a problem that's been totally solved. And I've given my suggestions. I've tried to base them in the landscape. But a lot of it is still inference. Because the ramps were dismantled once the pyramid was complete, only fragments of evidence are available to archaeologists. But it was ramps and sheer muscle power that allowed millions of blocks to reach the summit. Once in position, the builders faced a new task. The blocks had to be fitted together. Surprisingly, in such a precise build, a large proportion of the internal stones were just roughly finished. The gaps between them were filled with rubble and gypsum mortar. In between the blocks were stuffed lots of limestone chippings mixed with a huge dollops of mortar. And it's set just like modern concrete. But every stone that would be visible when the build was completed was placed with amazing precision. In the Great Pyramid, the blocks of the burial chamber fit precisely. The sides of these blocks had to be almost perfectly flat to make these astonishing joins. This precision engineering was achieved using the most rudimentary of tools. Yes, we'll use this rods and string tool in order to find out whether the surface is truly flat. And by using a third rod, which is the same length as the other two rods joined by the string, which is now pulled very taut, we can see if it just slips under. Now, we've got a bit of a high spot there. Now, in ancient times, they would mark that simply by putting some red ochre on just to remind the workers where to go to and check along the length of the string. The ancient mason would use the rods and string to spot imperfections and then mark them with red ochre to show where more work was needed. Using two further tools, this one being a flint scraper and this one being a sandstone rubber, now we can use the marks as a guide to scrape away the high point like so. And it's obvious that as you scrape, the mark disappears. And with this, of course, the high spot. This same technique was also used in the final stage of construction. The rough internal blocks were covered with an outer casing of perfectly smooth stone. This was carved from the highest grade limestone and had to be carried across the Nile to the pyramid site. With this polished casing, the pyramid would have shown dazzling white in the Egyptian sun. When the pyramids were newly encased in this special limestone, they must have been blinding in the sun like newly fallen snow. To achieve this, every casing stone was cut to sit perfectly with its neighbors. When complete, the Great Pyramid of Giza was covered with thousands of these facing stones. Sadly, they have long vanished, taken to build the mosques and castles of Cairo. But facing stones can still be seen on the cap of Khafre's pyramid. Even with all the Egyptian skills and tools, building the pyramids was still an incredibly hard task, requiring millions of man hours to complete. Legend has long suggested that the pyramids were built by armies of slaves. The legends are wrong. Forensic archaeological discoveries are now putting a face on the people who really built the pyramids. The building of the pyramids was an enormous construction project requiring incredible manpower resources. Ancient histories tell of 100,000 men laboring on the Great Pyramid for 20 years. Modern experts believe 25,000 workers is a more realistic estimate. The job was completed during Pharaoh Khufu's 23-year reign. The workers would have put in over a quarter of a billion man hours. Ancient Egypt was a rich land. But for such a mammoth undertaking, the builders would have had to source materials from across the whole country. The vast granite blocks had to be floated 600 miles down the Nile from the quarries at Aswan. Keeping a pyramid build on track was a logistical nightmare that would test even a modern engineering firm. Engineer Craig Smith has overseen vast construction sites and has analyzed how a pyramid build might operate. You don't have cell phones. You don't have pagers. You don't have laptop computers. You have millions of pieces of material that have to arrive at the right point in time. Egyptian communications depended upon papyrus and foot messengers. Yet they kept track of thousands of workers and countless millions of pieces of raw material. A present-day pyramid builder would have all the benefits of modern technology available to them. Were the Egyptians probably relied on the stars to align the pyramids, we would use lasers. Were the Egyptians use simple ramps, we would use giant tower cranes to raise the blocks. Today, motorized vehicles would transport building materials to the site. All the Egyptians had was muscle power and slow-moving boats. Craig Smith has calculated the cost of building a great pyramid in today's money. If you did it with limestone, it'd be about $4 billion and would take about four years. That's considerably less than the 23 years it's estimated it took to build the Great Pyramid. But we should not underestimate the scale of their achievement. The ancient Egyptian craftsmen would have had to place a block every two minutes, 270 blocks every single day for 23 years. And on top of its sheer scale, the pyramid was built to last for all eternity. We haven't built anything of that scale in recent times that probably has any likelihood of lasting 4,500 years. The Great Pyramid alone was a triumph of human ingenuity. But amazingly, the Egyptians built another 17 major pyramids. This pyramid building epic spanned five centuries and was perhaps the greatest construction project of all time. These pyramids are known by the names of the pharaohs who commissioned them. But the identity of the actual people who built them has long remained a mystery until now. It was thought that the pharaoh would never have forced his own people to toil for year after year constructing the pyramids. Instead, it was believed that they were built using slave labor, possibly the Israelites. In recent years, archaeologists have excavated the areas around the Giza pyramids. Their finds have radically changed the theories on who built the pyramids. Renowned Egyptologist Dr. Zahi Hawass has discovered the tombs of the actual pyramid builders. Dr. Hawass was surprised at the elaborate nature of these tombs. They do not look like humble burial grounds for slaves. Dr. Hawass' work is finally letting us see pyramid construction from the worker's perspective. But who were the actual workers? The answer comes from the new science of forensic Egyptology. Egyptologist Rosalie David works with biologists and artists who reconstruct the lives of the men who built the pyramids. Cat scans and 3D imaging resurrects faces of the ancient Egyptians from mummified skulls. This is the reconstructed face of an Egyptian who lived thousands of years ago. You do get a sense of the character of the person. They cease to be a wizened mummy or a dry skeleton. And there they are with the flesh, the eyes, the hair. You're looking at somebody who could be alive today. Forensic analysis of workers' bones provides conclusive evidence that the pyramid laborers were not foreign slaves. The idea that the pyramids were built by slaves is totally wrong. This has been proved, really, by the archaeological evidence. So all the studies on the bodies show that they are Egyptians. They're not from overseas. The bones also show clear evidence of medical treatment. Broken limbs have been reset. One skull even shows signs of early brain surgery. Foreign slaves would never have been granted such high-quality medical attention. But where was this native workforce housed? To Mark Lehner, the pyramid builders' town must have been near the Giza Plateau. If there were 20,000 people out there, to say nothing of 30,000, it would have been one of the largest cities in the world in the third millennium BC. So where was it, and where was all the infrastructure? Lehner's breakthrough came when he excavated a site to the southeast of the pyramids, next to the workers' tombs. Everywhere we put down an excavation trench, we find large, substantial mud brick walls, evidence of an ancient settlement. The layout of this long-hidden town exposes more and more about the lives of the pyramid builders. Well, the footprint of this lost city tells us something about how they organized their society in this very early period when they built pyramids. Feeding the workers may have been the biggest organizational challenge, and Lehner's team has found evidence that the craftsmen were well-catered for. From remains found on the site, it's clear that the pyramid builders received generous rations, including beer, meat, and fish. They were very well-organized. They were well-fed. They were looked after because they were very important. But it appears that the middle management may have been even better looked after. They were eating a lot of meat, sheep, goat, but especially cattle. They ate very well, but we're seeing that some people on the site ate better than others. Mark Lehner believes that this core of professional craftsmen and officials were kept on site. But the hauling of the blocks was carried out by villagers who came to work on the site for a few months or years. For these unskilled workers, pyramid building was a bit like military service. This was an army mobilized from the length of Egypt, but they came to build rather than to fight. What really fascinates me about the pyramids is not so much the king or the little man in the trenches, but the whole human network that could create something like the Great Pyramid of Khufu. But what drove the ancient Egyptians to dedicate so much energy and manpower to the pyramids? Why were thousands of men brought from across the country to labor on this site? These questions have intrigued archaeologists as they try to solve the third great mystery of the pyramids. What were they for? Back in medieval times, it was thought that the pyramids were the giant granaries of the biblical character Joseph. But most modern Egyptologists believe that they are tombs for the pharaohs, the largest and grandest tombs ever built. Although centuries of tomb raiding means that no remains of a pharaoh have ever been discovered inside a pyramid, and no mummy was ever found in the so-called burial chamber of the Great Pyramid of Khufu. Dr. Hawass, however, is convinced that there is enough written evidence to prove the pyramids were built as tombs for the pharaohs. There is lots of evidence in inscription and literature that's telling us that this is a tomb for the king. But a tomb for a pharaoh was more than just a resting place for his body. Deep within some pyramids is evidence of another more magical function. These tombs were built as gateways to the stars. The ancient Egyptians poured resources and manpower into building the pyramids, the greatest stone monuments on the planet. It's believed that they were built as tombs, but their true importance to both the pharaoh and Egypt itself remained hidden. For centuries, these silent giants kept their secrets until a discovery made by pure chance. In 1879, a workman was passing one of the later Saqqara pyramids at dawn when he saw a jackal. The beast seemed to be taunting the workman. Almost asking to be chased, the workman then followed the animal into a hole near the pyramid. To his surprise, he found himself in a chamber. Lifting his lantern, he saw that the walls were covered with hieroglyphs. These ancient sacred writings had been hidden for thousands of years. Jim Allen is a world expert on these hieroglyphs, or pyramid texts. He believes they give us a unique insight into the intentions of the pyramid builders. They are the oldest religious texts known from Egypt, which makes them one of the oldest bodies of religious texts in the world. The texts revealed nothing about how the buildings were built, but they do reveal the pyramids' ultimate purpose. The pyramids were not created as simple resting places for the pharaohs. They were built as giant machines for turning men into gods. The pyramid is like a cosmic engine. It is designed to transform the dead being beneath it into a living spirit. When the king died, the ancient Egyptians believed that Egypt and existence itself was plunged into mortal danger. Even after death, the ruler had to protect his country from drought, famine, and the forces of chaos. The mummified pharaoh was carried into his giant tomb along with food, clothes, jewels, and treasures, everything he would need in the afterlife in the stars. Salima Ikram has studied ancient Egyptian beliefs about the afterlife. The basic thing is it's very much like this life, except better. So everything you wanted in this life, if you have managed to put it into your tomb, you can have it in the afterworld. The pyramid texts leave a record of the rituals that were performed over the mummified body of the pharaoh. To ensure that he survived his journey to the afterlife, they also included spells and prayers to protect him. We tend to think of magic as abracadabra, wizards, witches, Harry Potter. To the ancient Egyptians, magic was a part of the universe. For the Egyptians, this was the science of survival. There is no superstitious mumbo jumbo in ancient Egypt. Everything has a meaning. Everything has a purpose. Once the rituals were completed, the pyramid was sealed, hopefully for all eternity. The pharaoh was then free to make his journey to the afterlife, to be reborn as an eternal star. But Robert Boval, who has written extensively on the pyramids, believes that there is a further connection between the stars and the pyramids. For years, he has been intrigued by the links between Egyptian religion and astronomy. It all started with an aerial photograph of the Giza pyramids. Boval noticed a very distinctive pattern. I was looking at monuments that had been laid according to a plan. There were two large pyramids set along a diagonal. What bugged me, what really got me, was there was a third smaller one offset from the diagonal. This faulty diagonal reminded him of the stars of Orion's belt. It has two bright stars and one dimmer star offset. The relative sizes and positions of the three Giza pyramids seem to match those of the three stars. For some Egyptologists, Boval's theory is just a coincidence. If you look at the stars in the Orion constellations, you'll find that they do not fit with all the Old Kingdom pyramids at all. You'll find maybe very few with computer you can really match them. Dr. Hawass argues that many other stars in the Orion constellation do not match the layout of any pyramids on the ground. But to Robert Boval, the correspondence was clear evidence of an astronomical master plan explaining the layout and design of the major pyramids. You cannot deny the fact that there are three stars that look like the plan of the pyramids. Two large ones, small one, offset. Two large pyramids, small one, offset. That is a fact. It's a fact. What isn't a fact is whether it is a coincidence or not. For Boval, there is another piece of compelling evidence within the overall design of the pyramids that backs his astronomical theory. There are four narrow shafts built into the structure of the Great Pyramid. Just eight inches wide, they climb upwards through the solid stone interior from the king's and queen's chambers toward the surface for over 200 feet. They were carefully built into each layer of stones as the pyramid rose. These stone shafts may hold clues to some of the last remaining mysteries of the pyramids. Originally, it was thought that the shafts were designed as air vents to bring fresh air into the pyramid for the workers toiling inside. However, for Boval, these shafts are far more significant. As he examined their orientation, he felt he was cracking a secret code, a code built into the very structure of the pyramid. But it was exciting to realize that I was beginning to listen to the silent language of the pyramid. Boval believes each of the four shafts running through the Great Pyramid is built to point directly toward a major star. What's more, each of these stars is critically important in the ancient Egyptian religion. One of the southern shafts points toward Sirius, the counterpart of the goddess Isis, while the other points to Al-Nitak, one of the stars in Orion's belt. This constellation was the heavenly equivalent of Osiris, the Egyptian god of death and resurrection. The star shafts may be aligned this way to help the spirit of the pharaoh ascend to heaven to join the god Osiris and become a star alongside him. For Boval, this realization was like solving an ancient riddle. So we have a kind of language, if you like. I call it astroglyphics. The pyramid speaks through its architecture and through its symbolic astronomy. Although Boval's theory is totally rejected by some Egyptologists, other mysteries and rumors still surround the shafts. Dr. Hawass believes that they may lead to unseen treasure within the pyramid's core. If I'm right, this will be the most important discovery in Egypt and in the world. The Great Pyramid at Giza contains a complex of shafts and chambers. Researchers have already discovered three possible burial chambers linked by corridors, including the magnificent Grand Gallery. But in recent years, interest has focused on four mysterious shafts that run from the king and queen's chambers toward the surface. These narrow channels are surrounded by rumors of hidden chambers and astrological links. In the 1980s, a French team studied the structure of the Great Pyramid using microgravimetric techniques which detect variations in the density of objects. Their study identified several areas of differing density, suggesting that there may be undiscovered chambers near the top of the pyramid. In 1993, Dr. Zahi Hawass worked with a German robotics team to explore the shafts in the queen's chamber. What they discovered rocked Egyptology. After 200 feet exactly, the robot was stopped in front of a door with two copper handles. The southern shaft was sealed by a solid limestone slab, which blocked the robot exploring further. In 2002, a different team went back with a more advanced robot. It carried drilling equipment designed to cut through the limestone panel. Remote sensing techniques, similar to those used to find earthquake survivors, had revealed that the slab was only three inches deep. The robot climbed up the narrow shaft and drilled a small hole just big enough for a tiny camera to pass through. What the camera revealed was totally unexpected. Another limestone door across the shaft. For some observers, it was a bitter disappointment. But for Dr. Hawass, this was still an important find. We're not looking for the doors of Ali Baba and the 40 thieves. We are looking for archaeology. Then anything that you discover inside the pyramid, it's a major discovery. Behind this second door is a region of the pyramid unseen for over 4,500 years. Dr. Hawass believes that a hidden chamber may lie behind the limestone slab. He is now ready to go back inside the Great Pyramid and believes he may find the ultimate archaeological prize. I still believe that the burial chamber of Khufu is still hidden inside the pyramid, that we're going to go through the first door and the second door to find out what is the mystery behind them. If Dr. Hawass uncovers the tomb, it could be the greatest find ever, greater even than the discovery of the tomb of King Tut. Here may lie the last mystery of the pyramids, the final resting place of Khufu, one of the greatest of pharaohs. Sealed since the day when the pyramid was finally completed and stood gleaming in the desert sun. The Great Pyramid is the only wonder of the ancient world left standing. Its polished stone casing has long gone, and it has lost 30 feet in height since it was built. But even at that rate, it might take another 65,000 years before it disappears from the skyline. The pyramids stand as a testament to the extraordinary skills of the people who built them. They tower over history itself, truly among the greatest achievements of mankind, past and present. They stand there against all the odds after thousands of years, and they trumpet immortality. As the ancient Arab proverb says, man fears time, yet time fears the pyramids.