The Aya Sofia (also Haghia Sophia) is a museum nowadays. It was founded as a church on a place where earlier another church stood. That was inaugurated on 15-2-360 during the reign of Constantius, son of Constantine the Great. That one was set alight and burned. During the Nika-uprising in 532 the Great Church, started under Theodosius II, which was the next church on that place, was also destroyed. Remains of that church can be seen at the West of the current church.
Tilted Arc," by Richard Serra and "The Thinker" by Rodin