Hagia Irene

Standing within the outer courtyard of Topkapı Palace, this former Byzantine church is among the oldest in the city, rebuilt by Emperor Justinian I in the sixth century after riots destroyed an earlier structure. Never converted into a mosque, it served the Ottomans as an armoury and later a museum, preserving an austere, largely unadorned interior. Its apse retains a simple mosaic cross from the age of iconoclasm, a rare survival from that turbulent period. Renowned for excellent acoustics, the vast domed hall now hosts concerts.