Basilica cistern is an ancient underground reservoir of Constantinople, located at a depth of 10-12 meters.The Basilica Cistern has the capacity to store 100,000 tons of water.

In the Depths of History. The Basilica Cistern Museum is one of the most important cultural assets where we can trace the traces of glorious Istanbul history. This grand underground cistern, built by Eastern Roman Emperor Justinian I (527-565), is nicknamed “Yerebatan Sarayı” (Sunken Palace) among the public due to its numerous marble columns rising from the water.