Cisterns in Istanbul
Beneath Istanbul lie vast Byzantine reservoirs. Here's a guide to the city's underground cisterns, from the Basilica Cistern to lesser-known sites.
Istanbul's Hidden Waterworks
Long before modern plumbing, Istanbul depended on an extraordinary network of underground reservoirs to survive. Built during the Roman and Byzantine eras, these cisterns stored the water that kept a growing capital alive, feeding homes, public baths, fountains and the gardens of its palaces. Today they survive as some of the most atmospheric spaces in the city, where rows of ancient columns rise from still, dark water beneath the busy streets above.
Visiting them is a striking change of pace from the sunlit monuments overhead. Cool, quiet and dramatically lit, the cisterns reveal the engineering ambition of the empires that shaped Constantinople and offer a welcome retreat on a hot afternoon.
The Cisterns Worth Knowing
The Basilica Cistern, or Yerebatan Sarnici, is the headline act. Commissioned in the 6th century under Justinian I, it could hold around 80,000 cubic meters of water and is supported by 336 marble columns standing some nine meters tall. Its most photographed feature is the pair of Medusa heads repurposed as column bases, and its location in Sultanahmet, just steps from Hagia Sophia, makes it easy to fit into any itinerary.
Beyond it lie several quieter alternatives. The Binbirdirek Cistern, dating to the 4th century, is the second largest, with 224 columns set in a grid that once served the Great Palace of Constantinople and now hosts cultural events. The 5th-century Theodosius Cistern, near the Grand Bazaar, showcases elegant columns and arches in a more intimate setting, while the vast Cistern of Justinian in the Fatih district, capable of holding some 250,000 cubic meters, remains closed to visitors.
Tips for Your Visit
To enjoy the cisterns at their calmest, aim for early mornings or late afternoons and favor weekdays over weekends. Spring and autumn bring the mildest weather above ground, though the cisterns stay cool year-round, so a light jacket is a good idea even in summer.
Plan for a short but rewarding stop of roughly half an hour to forty-five minutes. Comfortable shoes help on the stairs and damp floors, and a camera that copes well in low light will capture the mood far better than a flash, which is best avoided to preserve the atmosphere. Note that the underground setting and steps make accessibility limited for visitors with mobility challenges. Entry fees apply, with the Basilica Cistern priced above the smaller sites, and most open from around 9:00 AM to 7:00 PM, so check current hours before you set out.
FAQ
Which is the most famous cistern in Istanbul?
The Basilica Cistern, known in Turkish as Yerebatan Sarnici, is the largest and most visited. Built in the 6th century under Emperor Justinian I, it holds 336 marble columns and the famous Medusa head bases, and sits in Sultanahmet near Hagia Sophia.
How long does it take to visit a cistern?
A typical visit lasts about 30 to 45 minutes. The underground spaces are compact, so you can comfortably combine a cistern with nearby sights such as Hagia Sophia or the Grand Bazaar in the same outing.
Do I need a ticket to enter the cisterns?
Yes, the open cisterns charge an entry fee, with the Basilica Cistern costing more than the smaller sites. Most are open roughly 9:00 AM to 7:00 PM, though hours vary, and a few historic cisterns remain closed to the public.