Basilica Cistern, Istanbul

This underground cistern was built by Byzantine Emperor Justinianus (527 to 565). 140 meters wide, by 70 meters long, with 336 marble columns, each 9 meters in height. The capacity is 100,000 tons of water storage. 2 Medusa heads were taken from unknown locations and used as the base of 2 columns. The heads are the highlight attraction for most visitors.

For me it was the fish. Big carp, little carp and a few ginormous ones, all swimming and dodging coins in an almost perfect environment.

The English translation pamphlet sums up the experience of the cistern adventure best:

"The cistern, like in the past, has been going on its survival adventure with fish everywhere. The visitors melt into disappearance when they are here in the cistern to see the Medusa head, in accompany of fish and smoothing music."

And there you have it.