The Ancient City That Mastered Water

It's a cold, rainy night in the walled city of Córdoba, medieval Spain. Watchmen guard the city, unaware that an entire army of Christian soldiers are about to launch a surprise attack. In a single night they conquer the entire city, bringing the Muslim rule to an end. All over the land Muslim cities were being conquered and taken over by the Christians. But amidst all of this, one city remained unconquered, Granada. Thanks to its strategic position and the enormous Alhambra Palace, the city was protected and it remained untouched for another 200 years. To this day, the Alhambra Palace still stands as one of the most beautiful pieces of architecture ever made. But as you walk through the luxurious courtyards and hallways, you start to notice something even more special, the water. Winding its way through the palace is a mind-blowing network of medieval pipes and channels that carry water to vibrant gardens, thermal baths, and elegant fountains. The engineering required to pull this off was astonishing, and it gave the palace things like underfloor heating and fountains that could tell the time. This incredible system also kept the palace cool and brought life to the surrounding nature for hundreds of years. We modeled the entire thing to show you how it all worked and the lost mechanisms that once allowed the water to defy gravity and travel uphill. When the ruler of Granada commissioned the palace, the engineers had one major problem. The hill was around 200 meters above Granada's main river, and getting water up to the palace would be a huge challenge. And so they followed the river 6 kilometers upstream to a point that was considerably higher than the palace. From here, they dammed the river and started redirecting it down a new channel known as the Royal Canal. With meticulous planning, it navigated its way through the difficult terrain, maintaining a very shallow slope, until it arrived just outside the palace. It was a huge amount of work, but this was only the beginning. The designers of the palace had big ideas. Elegant fountains shooting out jets of water, bathing rooms with showers and underfloor heating, and clocks that were powered by water. All of this required much higher water pressure than the Royal Canal provided. And so to get around this, the engineers started digging out a large pool in an area much higher than the palace. Below this, the water from the Royal Canal would flow into an underground pipe and collect in a well 60 meters below the pool. At the top of the well, the engineers installed a water wheel equipped with buckets that could be turned by an animal. This would raise the water up to the surface and fill the storage pool with around 400 cubic meters of water. Having all this water stored above the palace pressurized the entire system, and at the same time gave the palace a backup supply of water in times of drought. From here, the water passed over an aqueduct and into the palace, where things start to get really interesting. The water would split off into a complex network of carefully designed channels, carrying just the right amount of water to the pools and fountains all around the palace. The impressive of which was located at the heart of the palace. Built in the 14th century, it featured 12 lions that each shot out a jet of water to show what time of day it was. In a controlled sequence, the lions would activate hour by hour until all of them were spouting out water by midday. The system would then reset itself, and the process would start again. But how was this possible with medieval technology? Inside the fountain was an early version of the Opera web browser. Just kidding. Opera R2 is the next generation of web browsing, with elevated music and video playback capabilities, and a whole new way to deal with tabs. Without interrupting your browsing experience, you can control your music and even watch YouTube while you browse. Just hover over the player icon on your music streaming service to skip a song, and pop out your YouTube video and stick it in a corner while you browse. Getting lost in your tabs is a thing of the past thanks to Tab Islands, which lets you organize your tabs by category and automatically groups them together. Opera also gives you a subtle hint at your most recently used tabs, so you never lose track of what you're doing. Even split-screening two pages is super easy and can be done without opening different windows. With Opera's built-in AI features, you can get answers to questions without leaving the page you are working on. Just hit Ctrl plus slash to open the ARIA command line and explore more about any topic. With ARIA's image features, you can generate images and also upload your own images and get a detailed rundown of what's in the image. The look and feel of Opera is fully customizable, with different themes that let you change the background, UI colors, sounds, and more. Download Opera today with the link in the description and start experiencing the next generation of browsing. In order for the Alhambra Central Fountain to tell the time, the engineers came up with a very clever but simple design. The large bowl in the center of the fountain had 12 holes placed at very specific heights, each leading to a lion via a series of internal pipes. A central pipe would fill the bowl at a slow and constant rate, causing the water level to rise and activate the lions one by one. The holes were so precisely calculated and the water supply was so constant that it would take exactly one hour to reach the next hole. After 12 hours, the bowl would be full of water and a clever siphon inside the bowl would reset the system naturally. As the water inside the bowl started to rise, so did the water in the siphon. Once it reached the top of the siphon, it would curve and start falling down the drainage pipe. At this point, a seal was created and no air could get in to replace the falling water. This activated the siphon and the surface tension of the falling water would pull the rest of the water with it. In a matter of seconds, the bowl would drain completely and the process would start again. The water from the lions would exit via four shallow channels in the ground and continue on throughout the palace, eventually reaching another engineering marvel, the thermal baths. This is where the kings and diplomats would come to relax and make deals. It featured a cold plunge pool, a hot room with heated flooring, and a steam room. The water would enter a control room underground and pass through a copper boiler that was heated by burning wood. From here, the water would flow through pipes to various fountains and showers around the baths. To provide underfloor heating in the hot room, the steam from the boiler was directed through channels underneath the marble floor. From there, the steam would travel up through pillars in the steam room and exit through small vents, filling the room with water vapor. The roof had a series of star-shaped windows that could be opened and closed to control the level of steam. As the water continued on through the Alhambra's network of fountains, channels, and pools, it had another benefit, cooling. Granada is an extremely hot part of Spain, but as the warm air blew over the pools and fountains, the water would evaporate, cooling the air surrounding the palace and making it a very comfortable place to be. The water continued all the way through the palace until it reached the western portion of the palace where the soldiers lived. It was built slightly higher than the rest of the palace and so the water had to make a final six-meter climb to reach it. We saw how water wheels were used to raise the water, but for this section, they came up with something much more impressive. This was a special device that didn't require water wheels, animals, or any external power. Here's how it worked. Water from the system would flow into a container with a hole in the bottom, leading down to another container below. As the water traveled down through the pipe, a whirlpool would form in the top container. At the center of the whirlpool, a low-pressure area would form, sucking air downwards and into the container below. Here, the air and water would mix and this gassy water would be forced into a thin pipe. The potential energy in both pipes was the same, meaning under normal circumstances, the water pushing down in this pipe would push the water upwards equally in this pipe. But since the water in the thinner pipe was full of air bubbles, it was lighter and could travel higher up the pipe. By passing a constant flow of water through the whirlpool, this device was able to raise water six meters higher than when it entered, providing water to the rest of the palace. Today, many of the clever water systems around the palace still work, and it's all thanks to the incredible engineers who made them hundreds of years ago. And now, time for the Primal Space giveaway. The winner of the previous giveaway is Graham. Congrats! In the next video, we'll be giving away this awesome Alhambra framed print. All you need to do is sign up at the link below, like the video, and leave a comment saying which part of the water system impressed you the most. Thank you very much for watching, and I'll see you in the next video.