Lexie Alford on Instagram: "One building, two religions When it was first built in Constantinople, Hagia Sophia was the largest Christian church in the world and the heart of Eastern Orthodoxy. After the Ottoman conquest it became a mosque, and for the past few decades it has been a museum open to all. Today it has been reopened as an active mosque. Visitors are only allowed on the second floor, while the main prayer hall downstairs is reserved for Muslims. Some of the Christian mosaics that are