The Basilica cistern is situated right next to the Hagia Sophia and opposite the police station. This cistern was used for the provision of water for the Great Palace in earlier Constantinopel. Right above the cistern was a basilica that’s why it’s called like this. The water within the cistern was brought from Belgrade back then and provided the emperor’s family and household. Sights in istanbul The cistern consists of twelve rows of 28 columns and can store up to 80,000 cubic metres of water. In the back of the cistern you can find two heads of medusa. The entrance fee is 15 TL.
It lies beneath the city of Istanbul. It is the largest of several hundred ancient cisterns. It was built 1400 years ago!