The Binbirdirek Cistern, also known as the Cistern of Philoxenos, is a subterranean reservoir near the Hippodrome. It was originally built in the fourth century AD beneath the Palace of Antiochus. The cistern was used up until the Ottoman conquest in 1453 when it was abandoned. In the 17th century it was rediscovered, though it has remained unused. The cistern is capable of holding 40,000 cubic meters of water.
The name Binbirdirek comes from Turkish and means "1,001 Columns", even though in reality there are only 224 columns. There is no water in the cistern, but you can hear a constant dripping. Different booths are scattered about with information about the cistern and Istanbul, and on occasion art exhibitions. There is also a cafe which provides visitors with complimentary coffee or tea.
The cistern is right in the heart of Sultanahmet. It's definitely not as impressive as the more famous Basilica Cistern. The columns are lacking the spectacular adornment, and the atmosphere is less mysterious. The crowds are also much smaller, and there is rarely a line, so if you're tired of Sultanahmet's crowds but really want to see a cistern, this is the place to be.
Location: Klodfarer Caddesi, Sultanahmet