The Forbidden Desert Civilizations: Lost Cities That Disappeared Without a Trace

Six thousand years ago, in the place we now know as the Sahara, there were cities full of people. And today, they lie buried beneath the sand, waiting. What happened to the Sahara happened to deserts all over the world. The Arabian Peninsula, Central Asia, the Gobi. Each of them was, at some point in the recent past, wetter, greener, and in each of them, people built things. Most of those things are still out there, waiting. The transformation of the Sahara from a green inhabited landscape to the dead desert we know today is one of the most dramatic climate events in human history. And it happened within memory of civilization. Geologists and climate scientists call it the African Humid Period, or the Green Sahara. It lasted from roughly 11,000 to 5,000 years ago. During this time, the Sahara received significantly more rainfall than today. Not occasionally, not in isolated pockets, but reliably and widely. The evidence is everywhere, buried just below the surface. In the Fezzan region of Libya, which today receives virtually no rain, researchers have found the dried beds of ancient rivers and lakes. In the Enedi Plateau of Chad, there are caves painted with giraffes, cattle, and human figures, surrounded by what is clearly depicted as grassland. In the Saharan sand, there are fossilized fish, hippo bones, and the skeletal remains of enormous crocodilians. These animals could not have lived in conditions anything like what exists in the Sahara today. They lived in a functioning African savannah ecosystem, complete with seasonal rains, permanent water, and the full richness of a warm, wet landscape. What ended it was a shift in the Earth's orbital cycle. A slow, gradual reduction in the amount of solar radiation hitting the northern hemisphere during summer, which weakened the monsoon system that had been feeding the Sahara with rainfall. The rains retreated south. The vegetation followed. The lakes dried. The rivers became fossil streambeds. And the people who had lived across this landscape for thousands of years had to go somewhere. The leading theory, supported by the timing of the Sahara's desiccation, is that the population of the Green Sahara moved toward the Nile Valley as the climate collapsed around them. That the sudden surge in population along the Nile, around 5,000 to 6,000 years ago, was the arrival of climate refugees from a dying continent. That the Egyptian civilization, one of the most extraordinary in human history, may have been built in part by people who had already seen one world end. But not everyone left, and not everything they built disappeared cleanly. In what is now the Libyan Sahara, a civilization called the Garamantes built an empire that lasted for over a thousand years. They built cities. They built roads. They built a system of underground aqueducts called fogaras that stretched for thousands of kilometers beneath the desert floor, tapping ancient fossil water to irrigate their fields. At their height, between roughly 500 BCE and 700 CE, the Garamantes controlled trade routes across the Sahara, connecting sub-Saharan Africa to the Mediterranean world. They traded in gold, slaves, and exotic animals. Roman historians describe them. Roman soldiers fought them. And yet, outside of specialist circles, almost no one has heard of them. Their capital was a city called Garama, buried under and around the modern Libyan town of Jama. Archaeological surveys of the region have revealed a landscape saturated with Garamantean remains. Fortified towns, agricultural terraces, cemeteries with thousands of tombs, and the extraordinary network of underground that made agriculture. The fogaras were engineering on a remarkable scale. Horizontal tunnels, hand dug through the rock and sand, sometimes running for kilometers, designed to intercept the groundwater table and channel it to the surface by gravity alone. No pumps, no machinery. Just an intimate understanding of hydrology, geology, and the landscape built up over generations. At their peak, there may have been 1,400 kilometers of these tunnels running beneath the Libyan desert. The Garamantes did not disappear overnight. They were gradually weakened by the same process that created the desert around them. As the fossil water in their aquifers was depleted and could not be recharged in a landscape that no longer received significant rainfall, they had built a civilization on the last reserves of an ancient, wetter world. And when those reserves ran out, the civilization went with them. But the tunnels are still there. Much of the city of Garamar is still there, buried under the sand and the modern town built on top of it. The Garamantes are one of the better known buried desert civilizations, which means that for every empire we have found and documented, there are likely others still hidden. In the Arab world, there is a legend of a city so magnificent and so wicked that God destroyed it. It is called Iram of the Pillars, or Ubar, the City of a Thousand Columns. The Quran mentions it. Ancient Arab geographers wrote about it. Explorers who crossed the Empty Quarter, the vast sea of sand dunes in the southern Arabian peninsula, for centuries heard stories of a lost city buried somewhere beneath the sand. Most people assumed it was a myth. In 1992, a team of researchers using satellite imagery identified a set of ancient caravan routes converging on a single point in the Omani desert. Multiple tracks, worn into the ground over centuries of foot traffic and camel caravans, all heading toward the same place. They followed the tracks to their convergence and began to excavate. They found Ubar. Or rather, they found what Ubar had become. Beneath the sand was the foundation of a large walled fortress city. Towers, walls, the kind of fortification that marked a major waypoint on the ancient incense trade route. The city had been a hub of the incense trade, sitting at the crossroads of routes that connected the frankincense forests of southern Arabia to the markets of the Mediterranean and Mesopotamia. The frankincense trade was one of the most valuable commercial networks in the ancient world. It made certain cities fabulously wealthy, and Ubar had been one of them. Then the ground gave way. Beneath the city was a vast underground limestone cavern. Over centuries of occupation, as wells were dug and the water table was drawn down, the cavern's ceiling weakened. At some point, the archaeological evidence suggests sometime around 300 to 500 CE, the cavern collapsed. The entire city sank. Towers, walls and everything within them dropped into the void below, then were buried by the sand that poured in behind. The city did not burn. It did not fall to invaders. It swallowed itself. The legend of God destroying Ubar for its wickedness is in this reading a memory of something real. A city that was there one day and gone the next. The ground opening beneath people's feet. A civilization vanishing into the earth as if it had never been. That kind of event does not need embellishment. It writes its own mythology. The Taklamakan desert in western China is one of the most hostile environments on earth. Its name translates, depending on the source, as something close to, you go in, you don't come out. Temperatures swing from blistering summer heat to extreme winter cold. The dunes shift. The sandstorms can last for days. There is almost no water. And yet, beneath the sand, there are cities. Not one, not two. A string of them, running along the ancient Silk Road trade route, buried under dunes that have been accumulating for centuries. The most famous is Lulan. Founded on the shores of a lake called Lop Nor, Lulan was a prosperous trading city that sat at the intersection of the northern and southern routes of the Silk Road. Chinese records describe it as a kingdom with a population in the tens of thousands. Merchants from China, Persia, India and Rome passed through its markets. Around the 3rd century CE, the lake began to shrink. The rivers that fed it shifted course, as rivers in arid regions do when the landscape changes around them. Without the lake, without the water, Lulan died. The inhabitants abandoned it. The sand moved in. And within a few centuries, Lulan had disappeared so completely that medieval Chinese travellers who retraced the old Silk Road routes could find no trace of it. It was rediscovered in 1900 by the Swedish explorer Sven Hedin, who stumbled on the ruins almost by accident during a desert crossing. What he found was astonishing. Wooden buildings still standing in the dry desert air. Documents preserved by the same aridity that had killed the city. Silk and grain, and everyday objects lying where they had been left more than a thousand years before. Lulan was not alone. Nearby, the city of Nier lay buried under a different set of dunes. And Miran, and Endera, and Khotan, which survived longer, but whose surrounding ruins tell a story of a much larger, older civilisation, buried around the edges of the living city. Each of these places was once green enough to sustain a population, rich enough to attract international trade, and important enough to appear in the records of the Chinese imperial court. Each of them is now sand. And archaeologists who have worked the region consistently note the same thing. They are finding the tops of the ruins. The lower levels, the older foundations, the deeper history is still buried, still untouched, still waiting. In the Gobi Desert, on the border of what is now Inner Mongolia and China, there is a ruin called Karakoto. In Mongolian, the name means the Black City. Karakoto was the capital of a kingdom called Xixia, a Tangut empire that controlled a stretch of the Silk Road for roughly two centuries before the Mongols came. In 1226, Genghis Khan sent his armies against Xixia. The Tangut people resisted. They resisted long enough to be remembered as one of the few civilisations that refused to simply submit. And Genghis Khan died during the campaign, though his armies completed the destruction after him. The legend of Karakoto says that when the Mongol army could not take the city by force, they diverted the river that supplied it. Cut off from water, the city's commander buried the treasury, placed a curse on anyone who disturbed the dead, and led the final defenders out to die fighting rather than surrender. Whether the curse is true or not, the Russian explorer Pyotr Kozlov, who excavated the site in the early 20th century, died in unusual circumstances. Several of his team members did as well. The locals refused to approach the ruins. What Kozlov found inside the city walls was extraordinary. Thousands of manuscripts, paintings, and Buddhist artifacts preserved by the desert air. Entire libraries of texts in a script and language that took decades to decipher. A city that had been sealed by sand and superstition and left almost entirely intact for seven centuries. The walls of Karakoto still stand. Parts of the city are still buried under sand drifts that have accumulated since the Mongol assault. It is not the only Gobi city. The desert hides dozens of similar sites, smaller way stations, outposts, abandoned monasteries, all belonging to civilizations that flourished when the Gobi was more hospitable and faded when the climate shifted against them. The Gobi has been expanding for centuries. Every generation the desert gains more ground, and every generation it buries a little more of what was there before. For most of human history, finding buried cities required either luck or local knowledge. A farmer striking something hard with a plow, a shepherd sheltering in a cave, and noticing the walls were carved. An explorer following rumors to a ruin half buried in sand. That is changing. Over the last two decades, satellite remote sensing has become one of the most powerful tools in archaeology, and the results in desert regions have been extraordinary. Satellites equipped with radar can penetrate the surface of dry sand to depths of several meters. In regions where the sand is dry enough and the buried material is dense enough, stone walls, fired brick, compacted road surfaces, the radar returns a different signal from the surrounding matrix. The technology has already produced stunning results. In southern Arabia, satellite surveys have revealed a network of ancient caravan routes extending through the Rub al-Khali, the Empty Quarter, the largest continuous sand desert in the world, that no one had suspected existed. The routes connect known oasis settlements and trading posts through terrain that was supposedly always impassable, suggesting that the Empty Quarter was, within the last few thousand years, routinely crossed by organized trade caravans. In the Sahara, satellite imagery has revealed ancient lake shorelines, river channels, and in some areas, geometric features on the ground that may represent the footprint of Some of these features appear in areas so remote that no ground survey has ever reached them. In the Arabian Peninsula, a researcher named Michael Petraglia and his colleagues have used satellite data to identify thousands of stone structures in the Saudi desert, a landscape so vast and so inhospitable that no ground survey had covered it systematically. Many of these structures, including mysterious rectangular platforms and geometric arrangements of stones, date to periods when the Arabian interior was wetter and more inhabited. Most of them have never been excavated. We do not know who built them or what they were for. We know they are there because a satellite told us. What the satellites are showing us is not the full picture. They are showing us the outline of the full picture. The actual excavation, the actual story of who built these things and why and what happened to them, that work has barely begun. The Arabian Peninsula has a historical reputation as a land of nomads, tent-dwelling Bedouin, moving with their herds across the desert, with no fixed cities and no complex civic life. This reputation is partially accurate for the last thousand years or so, but it is wrong for the thousands of years before that. The Arabian Peninsula went through its own version of the Green Sahara. During the early Holocene, roughly 10,000 to 6,000 years ago, it received far more rainfall than today. Rivers flowed through what are now dry valleys, lakes formed in the interior. The landscape supported large herbivores, extensive grasslands and, increasingly clearly, substantial human settlement. The ancient kingdom of Sheba is typically placed in what is now Yemen and Ethiopia. But some researchers believe a significant portion of Sabaean civilization extended into the now desert interior of the Arabian Peninsula and that the lost cities of that world are buried under dunes that the satellite imagery is only beginning to penetrate. The frankincense and myrrh trade routes of the ancient world are another clue. These routes ran from the forests of southern Arabia northward to the Mediterranean and Mesopotamia. They were not thin tracks travelled by a handful of traders. They were arteries of an economy that lasted for centuries, supporting populations all along their length. Those populations needed water. They found it in wells, in seasonal rivers, in underground aquifers that were, at the time, still being recharged by rainfall that no longer falls. When the climate shifted, the wells went dry. The caravans rerouted. The settlements that depended on them emptied out and the sand came. Archaeologists who have worked in Yemen and southern Oman describe a landscape of extraordinary richness just beneath the surface. Ancient field systems, irrigation works and the buried walls of settlements that appear from what little excavation has been done to be older and larger than anyone expected. The problem is access. Political instability, conflict and the sheer physical inaccessibility of much of the Arabian desert interior have made systematic excavation nearly impossible. The cities are there, the sand is covering them and the world has not yet found a way to look. What happened to the Sahara, to the Arabian Peninsula, to Central Asia, what turned all of these inhabited thriving landscapes into the deserts we know today, was not a single catastrophe. It was a process. A slow, irreversible tightening of the climate that took centuries, sometimes millennia, to complete. But within the span of any individual civilization, it could have felt catastrophic. Imagine living in a city that your grandparents built on the shore of a reliable lake. Your parents watched the lake shrink. By your generation, the springs that fed the fields are running dry. Your children will be born into a world where the water is gone. That is the story of Lulan, of Ubar, Aramantian cities, of dozens of settlements across the Sahara, whose names we do not know and whose people left no written record of what they endured. The climate does not announce what it is doing. It just tightens year by year, decade by decade, until the accumulated weight of the change becomes impossible to live with. The civilizations that survived were the ones that could move. Those that could not, because their infrastructure was fixed, because their agriculture was tied to specific water sources, because they had invested too much in the built environment to abandon it easily, stayed until the end. Some of them left. They appear in other places, in migrations that archaeology is still tracing, carrying skills and knowledge that transformed the societies that received them. Some of them stayed and died, and some of them, the last holdouts in the most remote places, simply became sand. Their cities are still out there, not destroyed, not burned, not conquered, just buried, waiting under dunes that have been accumulating for 5,000 years in some of the most inhospitable places on earth for someone to come and look. The world's deserts cover roughly a third of the earth's land surface. Most of that surface has never been excavated. Most of it has barely been surveyed. The satellite imagery that has been analyzed represents a fraction of what exists, and even that fraction is producing discoveries faster than archaeologists can investigate them. Under the sands of the Sahara lie river systems that once sustained populations across the entire northern half of Africa. Under the Arabian sands lie cities that traded with Rome and Mesopotamia, while Rome was still a collection of villages on seven hills. Under the Central Asian dunes lie the capitals of empires that once controlled the flow of silk and spice across half the world. None of this is speculation. We know these things existed because we have found the edges of them. What we have not found is the center. The most important discoveries in desert archaeology are almost certainly still ahead of us. As the satellite technology improves, as political stability returns to some of the regions where the most significant sites are located, as the archaeological community begins to take the scale of buried desert civilization seriously, the picture will change. It will not be a slow accumulation of minor finds. The history of desert archaeology has been punctuated by moments of complete surprise. Ubar found by following ancient tracks, Lulan stumbled on by a lost explorer, the Saudi stone structures revealed by a single satellite pass. When the next major discovery comes, it will almost certainly arrive the same way, without warning, in a place where no one thought to look. The deserts are not empty, they never were. They are the world's largest archive, written in buried stone and compacted sand, waiting for the moment when we have the tools and the will to read them. Which desert do you think is hiding the greatest lost civilization? And what do you think we'll find when we finally look beneath the sand? Tell us in the comments below. And remember to give this video a like so it can reach more people. Keep your minds open and until we meet again.