A few steps from Hagia Sophia, a staircase leads down to a forest of columns standing in shallow water. The Basilica Cistern, known in Turkish as Yerebatan Sarnıcı, is one of the most atmospheric places in Istanbul.
A Byzantine reservoir
The cistern was built in the 6th century under Emperor Justinian I to store water for the Great Palace and the surrounding city. Its roof is carried by 336 marble columns, many of them reused from older buildings, arranged in rows across a hall roughly 140 metres long.
The Medusa heads
Two columns in the northwest corner rest on carved Medusa heads, one placed sideways and one upside down. Why they were set this way is still debated.
Visiting
After a long restoration the cistern reopened in 2022 with walkways and lighting that show off the columns. Visits take around half an hour, and it combines easily with Hagia Sophia, the Blue Mosque and Topkapı Palace on the same day.
