The Underground Cistern is located near the Saint Sophia Church in the Sultan Ahmet district.
The Turks call it "Yerenbatan Sarayi" which means "underground palace". The cistern was built by Justinian in the 6th century.
It is 70 meters wide and 140 meters long, with a capacity of 80,000 cum. of water. The cistern is supported by 336 beautiful beautiful columns two of which are carved with the head of Medusa on the plinth.
The cistern has been renovated and is open to the public every day of the week.While inside, you can enjoy classical background music, the differently illuminated columns and watch fishes swimming in the water.
And at the end of the tour you can also throw a coin and make a wish ...