The second largest Byzantine church in Constantinople, Hagia Eirene - or "Holy Peace" - sits just inside the walls of Topkapi Palace on First Hill. Restored from near-ruin by Justinian in the sixth century, it served as an Orthodox church for almost one thousand years.
After the Ottoman conquest, the Sultan's Janissaries used the building as an armory owing to its close proximity to the new royal palace. Today, however, neither prayers nor guns fill this space with any regularity. Its primary use is as a music hall.