Basilica Cistern underground palace

Basilica Cistern underground palace is one of the ancient remains of the city of Constantinople and the ancient underground water tunnels largest of Istanbul.
Basilica Cistern was used as water storage for the palace. After which the city was long forgotten until it was discovered after local people used as a garbage dump. The present water tunnel, this seems to be different from the traditional objectives and design a lot.
But it still represents a dramatic elements in engineering. The tunnel is a large size of marble pillars to 336 on space almost 2.4 acres.