Hidden Istanbul: The Basilica Cistern

The Basilica Cistern, Istanbul, is one of the city's most mysterious ruins. Find out it's history!

At Walks of Turkey we love sharing the most wondrous part of Turkish culture with fellow travelers. If you want to see the Basilica Cistern, Istanbul yourself, in the company of an expert guide, take a look at our Istanbul in a Day Tour and Best of Istanbul Tour

Disappearing into the belly of a cistern and encountering dimly lit Byzantine columns, mythical monsters and a healthy population of freshwater fish may sound more like a fantasy novel than reality but it’s all possible in the ‘Underground Palace,’ of the the Basilica Cistern, Istanbul. Though lacking the awe-inspiring magnitude of the Hagia Sophia or Topkapı Palace, the Basilica Cistern (or Yerebatan Sarayı as it’s known locally) is still one of the neatest things to do in Istanbul, and one the city’s most atmospheric sights. If you want to know what else we recommend seeing and doing in the city, check out our blog on the best things to do in Istanbul.

The Medusa Head Column is just one of the mysterious structures in the Basilica Cistern, Istanbul. Find out what other mysteries lurk in this fantastic attraction.

The Basilica Cistern was never meant to be part of the hidden Istanbul. It was built to provide fresh water to the city in the 4th Century AD, during the reign of the Emperor Constantine, before being enlarged in 537AD. Though Istanbul is bordered on three sides by water in the form of the Black Sea, the sea of Marmara and the Bosphorus, none of it is drinkable. For Istanbul to survive, never mind thrive, it was essential to have a good water supply and storage.

Water was transported to the underground cistern in Istanbul from the Belgrade Forest (which still exists to the north of the city and is one of the better Istanbul attractions in its own right) via a series of impressive Byzantine aqueducts, several of which are still standing today. The Valens Aqueduct even passes over one of the city’s main roads, filtering cars through its narrow archways. Once stored, the water was then used to supply the Great Palace during the Byzantine Empire and the Topkapi Palace during the Ottoman Empire.

Perhaps the most interesting features of the Basilica cistern in Istanbul are the Medusa heads used as plinths for columns supporting the vaulted ceiling. Medusa was the mythical monster of Greek mythology who had snakes for hair and could turn hapless adventurers to stone just by looking them in the eyes. Although there are plenty of theories as to where the large, beautifully-carved stone heads came from, their origins remain mysterious. It seems that they were repurposed from an earlier edifice, possibly a temple, but what that temple was dedicated to is lost to history. It’s postulated that they were turned on their sides and upside down when used in the cistern as a way of removing the monster’s powers. Whatever they case may be, their mystery and craftsmanship make them both awe-inspiring and strangely haunting, much like the mythical Medusa herself. You can read more about these stone wonders over at our blog on the Medusa heads.

Medusa head blocks cut from solid stone form the bases of some of the columns in the Basilica Cistern, Istanbul. Find out what other secrets this mysterious underground grotto harbors.

She may not look all that fearsome here, but Medusa was one of the greatest monsters of antiquity.

Did You Know…

While it may draw in crowds today, the Basilica Cistern, Istanbul actually lay forgotten for hundreds of years.  It was only when the curious French traveler, Petrus Gyllius (aka, Pierre Gilles) was visiting Istanbul in 1545 that it was rediscovered. Although he was officially in Constantinople looking for ancient manuscripts, the naturally curious Petrus noticed locals in the neighborhood around Hagia Sophia selling freshwater fish despite there being no freshwater sources nearby. After a bit more snooping he found that the innovative Istanbulites had sunken wells into a water source below their homes. And they weren’t only drinking from it, they were also catching fish from it.

When Petrus first explored the Istanbul’s underground cistern (which, by the way, is roughly the size of two football fields), he did so with little more than a row boat, a sketchbook for mapmaking, and a stout torch. These days the water level has been reduced so as long as you stick to the walkways you won’t have to worry about getting wet at this top Istanbul attraction.

The cistern features in the 1963 James Bond film, From Russia With Love, when a young Sean Connery rows across it, a la Petrus Gyllius, but with better lighting. It’s also the setting for the climax of Dan Brown’s 2013 book, Inferno, following the equally adventurous Robert Langdon’s fight to save the world.

Just in case you haven’t counted them yourself, you might be interested to learn that there are 336 columns laid out in 12 rows of 28. At 143 meters in length and 65 meters across, the cistern feels like an underground cathedral. If it were filled to capacity it would hold 17.5 million gallons of water.

Local Tip

The beautiful Hen's Eye column in the Basilica Cistern.

The Hen’s Eye column is another example of beautifully-carved stone, probably repurposed from an existing structure, that adorns the Basilica Cistern.

There were once around 80 underground cisterns in Istanbul. While the Basilica Cistern may be the largest and best-displayed Istanbul cistern, there are others that you can visit. Our favorites include the 1001 Direk (Binbirdirek) Cistern in Sultanahmet and the Sultan Sarnıç in Fatih (just next to the Yavuz Selim Sultan Mosque). Both of these are used to host weddings, celebrations and other events. But even with events on they are usually open to the public. If you’re lucky you might even come across a Turkish wedding in full swing – an experience not be missed.  Another cistern is located beneath the Nakkaş Oriental Rugs & Textiles shop in Sultanahmet and sometimes plays host to concerts and art exhibitions. Even if there’s nothing on when you drop by, the shop assistants will gladly let you look around.


The Basilica Cistern is open every day from 9am – 5:30pm.

The long line that snakes into what looks like a tardis, as visitors disappear into the ground, may be off-putting for some but you can beat it by going first thing in the morning. Also, it’s best avoided the Basilica Cistern completely on weekends when domestic tourists add to the numbers of visitors.

The entrance to the cistern is located just a stone’s throw from Hagia Sophia and the Blue Mosque. Walk a little farther and you can easily get to the Topkapı Palace and Istanbul Archaeology Musuem. Our favorite combination of these Istanbul attractions is to start the day at the Basilica Cistern then head to the Topkapi Palace to see where the water went and how it was used.

If all that sightseeing is making you hungry, stop into one of Istanbul’s oldest meatball joints, Tarihi Sultanahmet Köftecisi for a quick and very tasty bite. If you’re more in the mood for something sweet, try the famed Pudding Shop (aka Lale Restaurant) – once an important stop off on the ‘hippy highway’ and an iconic resting and meeting place for travelers.


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