Hagia Irine

St Irene is built in 537 by orders of Byzantine Emperor Justinian 1 st together with Haghia Sophia. It is a Greek Orthodox Church. After Istanbul had been conquered, the church stayed within the walls surrounding Topkapi Palace. It has never been used and turned into a mosque. The building was used as the royal arsenal since the first day after Istanbul was conquered by Ottomans until 1846. Having fantastic acoustics, the building today is home to many concerts performed within Istanbul Music Festival.