Basilica Cistern Istanbul

An Underground Wonder of Constantinople

The Basilica Cistern, called Yerebatan Sarnici in Turkish, is one of Istanbul's most atmospheric sights, and a deceptive one: despite the name, it is not a church but a colossal underground reservoir. It was built in 532 AD under the Byzantine emperor Justinian I to store water for the Great Palace and the surrounding buildings of Constantinople, with a capacity of some 80,000 cubic meters. After centuries of use it slipped from memory, only to be rediscovered in the 16th century by an Ottoman traveler who found locals drawing water, and even fish, through holes in their basements.

The scale is the first thing that strikes you. The chamber stretches roughly 138 by 64.6 meters, around 9,800 square meters, its roof carried by 336 marble columns standing nine meters tall in twelve orderly rows. The columns mix Corinthian and Ionic styles, many of them salvaged from older structures, and walkways now thread between them above the shallow water.

The Medusa Heads and Other Mysteries

The cistern's most famous features lie in a far corner: two great Medusa heads reused as column bases, one set on its side and the other upside down. No one is certain why they were positioned that way, which only adds to their allure. Elsewhere, the so-called Tear Column is carved with teardrop motifs traditionally read as a memorial to workers who died during construction. Live fish still glide through the water, a quiet indicator of its cleanliness and a remnant of the cistern's long second life.

Visiting the Basilica Cistern

The cistern sits in the heart of Sultanahmet, a short walk from Hagia Sophia and the Blue Mosque, and is easily reached on the T1 tram at the Sultanahmet stop. It is generally open from around 9:00 AM to 7:00 PM, though hours are worth confirming before you go, and ticket prices differ for local and international visitors. Wear comfortable shoes, as the surfaces are wet and can be slippery, and aim for early morning or late afternoon to avoid the heaviest crowds. Photography is allowed, but flash and tripods are not, and access is limited for wheelchairs because of the stairs. A typical visit runs 30 to 45 minutes, easily slotted between the other landmarks of the old city.