The Emperor Justinian ordered the construction of the Hagia Sophia (Holy Wisdom) during the 6th century. Built on the basilica style, the sheer size of the structure can't be imagined until you walk in the doors. Constantius, the son of Emperor Constantine, constructed the first church building on this site but it and the structure that replaced it were both destroyed by fire. When Islam conquered the region the minarets were added and the frescoes and mosaics, such as the one below, were covered. Today it is a museum and the Christian art is being restored.