Column with Medusa head in the Basilica Cistern Istanbul
At the base of two of the 336 columns in the cistern are two heads of Medusa. One is upside down and the other is sideways. Why they were placed that way is unknown. The cistern, located 500 feet of the Hagia Sophia on the historical peninsula of Sarayburnu, was built in the 6th century during the reign of Byzantine Emperor Justinian I.