The Binbirdirek Cistern, also known as the "Cistern of Philoxenos," measures 64 × 56.4 meters and features 224 columns, each topped with simple, rounded imposts—suggesting they were newly made. It served as a castellum aquae (terminus) for the Valens Waterway. While the Patria of Constantinople links it to a Philoxenos from Constantine I’s time, brick stamps date its construction to the mid-5th or 6th century, complicating this identification. Bardill (1997) even associates the "Cistern of Philoxenos" with the Bab-ı Ali Caddesi Cistern instead.

The cistern was repurposed for silk spinning in the 16th century, later topped by a 17th-century palace, and returned to silk production in the 19th century. Excavated in 1911, it became a marketplace before transitioning to museum administration in the 20th century. Today, it functions as a cultural center and special event venue.