To the West of the Hippodrome, the Binbirdirek Cistern is the second largest cistern in Istanbul. Built in the 4th century, the cistern is supported by 224 columns, each made of marble stone, which was brought from the Marmara Island. Its origin use was forgetten and it would be used for workshops until the rediscovery during the construction of a palace on the same site in the 17th century.