The largest and most noteworthy of these cisterns is Yerebatan Sarnıcı or the Basilica Cistern, located on İstanbul’s Historical Peninsula.

Built in the 6th century BCE, the Basilica Cistern is an impressive 9,800 square meter cistern capable of holding 80,000 cubic meters of water. Today, little water is kept in the cistern so as visitors can walk between the impressive ancient columns in the dim cavernous space.

The eerie atmosphere, which was even used for the set of a James Bond film, is punctuated at the end by a column resting upon a base featuring an upturned Medusa head.

It is said that the Medusa was placed upside down so as to nullify the power of her gaze to turn those who look at her into stone. But, rest assured, the only danger facing visitors to the Basilica Cistern is an urge to return again and again to experience its captivating ambience.