Lonely Planet review
When those Byzantine emperors built something, they certainly did it properly! This extraordinary cistern, built by Justinian in 532, is a great place to while away half an hour, especially during summer when its cavernous depths stay wonderfully cool.
Like most sites in İstanbul, the cistern has a colourful history. Known in Byzantium as the Basilica Cistern because it lay underneath the Stoa Basilica, one of the great squares on the first hill, it was used to store water for the Great Palace and surrounding buildings. Eventually closed, it seemed to have been forgotten by the city authorities sometime before the Conquest. Enter scholar Petrus Gyllius, who was researching Byzantine antiquities in 1545 and was told by locals that they could obtain water by lowering buckets in their basement floors. Some were even catching fish this way. Intrigued, Gyllius explored the neighbourhood and discovered a house through whose basement he accessed the cistern. Even after his discovery, the Ottomans (who referred to the cistern as Yerebatan Sarayı) didn't treat the underground palace with the respect it deserved and it became a dumping ground for all sorts of junk, as well as corpses. It has been restored at least three times.
The cistern is 65m wide and 143m long, and its roof is supported by 336 columns arranged in 12 rows. It once held 80,000 cubic metres of water, pumped and delivered through nearly 20km of aqueducts.
Constructed using columns, capitals and plinths from ruined buildings, the cistern's symmetry and sheer grandeur of conception are quite extraordinary. Don't miss the two columns in the northwestern corner supported by upside-down Medusa heads, or the column towards the centre featuring a teardrop design.
Walking on the raised wooden platforms, you'll feel water dripping from the vaulted ceiling and may catch a glimpse of ghostly carp patrolling the water. Lighting is atmospheric and the small cafe near the exit is certainly an unusual spot to enjoy a cup of çay.