The Cistern of Philoxenos (Greek: Κινστέρνα Φιλοξένου), or Binbirdirek Cistern, is a man-made subterranean reservoir in Istanbul, situated between the Forum of Constantine and the Hippodrome of Constantinople in the Sultanahmet district.

[2] The 224 columns, each 14 to 15 meters tall, are made of marble from nearby Marmara Island.

[2] The cistern was restored by Justinian I in the 6th century, after the Palace of Lausus was completely destroyed in a fire in 475.

After the conquest of the city by the Ottomans in 1453, the cistern fell into disuse, and was forgotten until rediscovered during the construction of Fazli Pasha's palace on the same site in the 17th century.

[2] In 1826, roughly 100 members of the Janissary Corps drowned after fleeing into the cistern during the Auspicious Incident.