Welcome to the Basilica Cistern

Welcome to the Basilica Cistern. You are now inside a structure built roughly fifteen hundred years ago, in the historic heart of Istanbul. The space you are visiting today was once an important part of the system that supplied Constantinople with water. But this is no ordinary water reservoir. Hundreds of marble columns support the ceiling of a vast underground hall. The arrangement of the columns and the sheer size of the structure give it the appearance of a palace. That is why it is also known in Istanbul as Yerebatan Sarayı, the "Sunken Palace." Yet the building was never used as a palace. Its original purpose was to store the water the city needed. Before you stands an important monument that carries the architectural and engineering vision of the Eastern Roman Empire into the present day. Throughout our tour, we will explore why the cistern was built, how it worked, and the remarkable historical details found inside. First, let's look back at the period in which this structure came into being: sixth-century Constantinople.