|Spooky place, this Cistern (my photo)|
The Basilica Cistern's water came from the Eğrikapı Water Distribution Center in the Belgrade Forest, which lie 19 km (12 mi) north of the city. It traveled through the 971 metres (3,186 ft)-long Valens (Bozdoğan) Aqueduct, and the 115.45 metres (378.8 ft)-long Mağlova Aqueduct, which was built by the Emperor Justinian.When you enter the cistern, you go down 52 stone steps, and it's very dark and dank, with water dripping off the ceiling. There are walkways that have been constructed around the places one might wish to see, which are some of the more amazing columns. Also according to that link,
The majority of the columns in the cistern appear to have been recycled from the ruins of older buildings (a process called 'spoliation'), likely brought to Constantinople from various parts of the empire, together with those that were used in the construction of Hagia Sophia. They are carved and engraved out of various types of marble and granite.And over in a far corner of the cistern, there are two columns with the image of Medusa on them. The first one, shown here, is sideways, with speculation that it's to blunt the power of her gaze. (But nobody knows for sure.)
|The first Medusa column base|
|The second Medusa head|
Forgotten by the city authorities some time before the Conquest, it wasn't rediscovered until 1545, when scholar Petrus Gyllius was researching Byzantine antiquities in the city and was told by local residents that they were able to miraculously obtain water by lowering buckets into a dark space below their basement floors. Some were even catching fish this way. Intrigued, Gyllius explored the neighbourhood and finally accessed the cistern through one of the basements.And it only became a tourist attraction in Istanbul in September 1987, the renovation of which was spearheaded by the Istanbul Metropolitan Museum. They cleaned it up and replaced boats with the walkways inside and now clean up in a different way by extracting 20 Turkish lira from each tourist.
It's definitely a place I'm glad to have seen, and the links I've provided will give you the whole history of the cistern. Don't miss it if you travel to Istanbul.