The Ancient City That Mastered Water
It is a rainy, cold night in the walled city of Cordoba, medieval Spain. The watchmen were present to guard the city unaware that an entire army of Christian soldiers were about to attack them by surprise. By the end of a night, they conquered the entire city and brought an end to the Muslim rule. Over the land, all Muslim cities were being captured and taken over by the Christians.
But in the midst of all 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.
The Alhambra Palace’s Water System
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 that it took to accomplish this was astonishing, and it gave the palace things like underfloor heating, and fountains that could tell the time. This incredible system kept the palace cool and brought life to the surrounding nature for hundreds of years, and it still works to this day.
We modelled the whole thing to show you how it all worked and the lost mechanisms that once allowed the water to defy gravity and travel uphill.
The Alhambra Palace’s Water System is a marvel of medieval engineering that reflects the sophistication of Islamic architecture and design. The Alhambra, located in Granada, Spain, stands as a testament to the ingenuity of the engineers who designed its waterworks. The system was created not only to provide essential water for daily life but also to enhance the beauty and ambiance of the palace, creating an atmosphere of tranquility and harmony with nature.
The water system was intricately designed to supply water to the palace’s extensive network of gardens, courtyards, baths, and fountains. The Alhambra is situated on a hill, which posed significant challenges in bringing water from the nearby rivers up to the palace. The engineers solved this problem through a combination of gravity, intricate channel systems, and hydraulic mechanisms that drew water from the Darro River. The system included a network of aqueducts, cisterns, channels, and waterwheels that ensured the continuous flow of water throughout the complex.
One of the most remarkable aspects of the Alhambra’s water system was its ability to provide not just a water supply but also cooling and heating functions. The system was responsible for both the cooling effect of fountains and the warming of baths through the use of underground pipes that circulated hot water. In addition, the waterwheels were used to raise water to higher levels, ensuring the efficient distribution of water to all parts of the palace, even those on higher ground.
The engineers of the Alhambra made excellent use of the natural topography, leveraging the differences in elevation to move water with minimal effort. They employed advanced techniques such as siphons and hydraulic pressure systems to maintain the flow of water across long distances and at varying heights.
The skillful use of water also created aesthetic experiences: the water in fountains and pools was designed to reflect the architectural beauty of the palace, creating an atmosphere that blended nature with human creation.
Overall, the water system of the Alhambra Palace was a masterpiece of hydraulic engineering, showcasing the high level of technical expertise of its designers and the cultural importance of water in Islamic art and architecture. The system not only served practical purposes but also elevated the aesthetic experience of the palace, contributing to the sense of serenity that continues to captivate visitors to this day.
Engineering Water Pressure in Medieval Times
The engineers had one major problem, as the ruler of Granada commissioned the palace when the hill was approximately 200 meters above the main river in Granada and getting water up to the palace would be an incredible task. 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 an enormous 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 bypass the problem, the engineers began digging out a great pool in an area that was much higher compared to the palace.
The water from the Royal Canal would flow into an underground pipe and collect into a well 60 meters below the pool. At the top of the well, the engineers fixed a waterwheel, attached with buckets that could be turned by an animal. This would push the water up to the surface and fill the storage pool with about 400 cubic meters of water. All this water stored above the palace was putting pressure on the entire system and at the same time gave the palace a supply of water in times of drought.
From here, the water traveled over an aqueduct and into the palace, where things become really interesting. The water would bifurcate and split off into a complex system of channels that all had their water content pre-calculated, transporting just the right amount to the pools and fountains dotted around the palace.
The Lion Fountain’s Water Clock Explained
The most fantastic of these fountains would be located in the very core 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.
In order for the central fountain of Alhambra to tell time, engineers came up with a very very simple but ingenious design. The large bowl placed centrally in the fountain had 12 holes at very particular heights, leading a lion through a set of pipes located inside.
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. When it reached the top of the siphon, it would curve and start falling down the drainage pipe. At this stage, a seal was formed and no air could penetrate to displace the falling water. This triggered the siphon and the surface tension of the falling water would drag the rest of the water with it. Within seconds, the bowl would drain completely and the cycle would repeat.
Thermal Baths and Underfloor Heating
The water from the lions would seep out through 4 shallow channels in the ground and continue on throughout the palace, until it would end up at 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 hot 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 rise up through pillars in the steam room and out of 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.
Cooling the Alhambra Palace
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 6-meter climb to reach it.
Gravity Defying Medieval Technology
We saw how waterwheels were used to raise water, but for this section, they came up with something much more impressive. This was a special device that didn’t require waterwheels, 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 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 through a thin pipe.
Now, under normal circumstances, the water pushing down on this pipe would push water up equally in this pipe. However, because the water in the thinner pipe was full of air bubbles, it was lighter and could travel higher up the pipe. This device was able to raise water 6 meters higher than when it entered, providing water to the rest of the palace.
Nowadays, many of the smart water systems surrounding the palace are still functional, and everything is because of the fabulous engineers who created it several hundreds of years ago.
