The Church of the Holy Saviour in Chora is a medieval Byzantine Greek Orthodox church preserved as a museum in the Edirnekapı neighborhood of Istanbul. In the 16th century, during the Ottoman era, the church was converted into a mosque; it became a museum in 1948. The interior of the building is covered with some of the oldest and finest surviving Byzantine mosaics and frescoes; they were uncovered and restored after the building was secularized and turned into a museum.