Exploring Istanbul’s most atmospheric underground space You know that feeling when a city suddenly gets quiet and you realize you have stepped into a completely different world? That is the Basilica Cistern. One minute you are walking past street vendors and honking cars near Hagia Sophia. The next, you are entering a totally nondescript building and descending underground into cool air, dripping water, glowing arches, and a place that feels like a cinematic dream sequence. I