The Basilica Cistern is without a doubt one of the coolest, human made places I have ever been. I don’t think you need to be an engineering nerd like myself to find the place to be really neat. It is an underground cistern built in 532 A.D. It is a wonderful example of engineering and was used to store water. Now it is a tourist attraction complete with a cafe. Yes, there is a cafe, and in my opinion, it would be only more perfect if it was a Starbucks simply because they are everywhere. The cistern was featured in the James Bond movie ‘From Russia With Love.’ Two of the columns have Medusa heads as bases, possibly because they fit and were available. There is still water in it below the walkways, and fish live there. They were introduced to keep the water clean.