One of the most important Byzantine monuments of Thessaloniki is in Chortiatis, in the center of the settlement, next to the church of Agios Georgios. This is the Church of the Transfiguration of the Savior, which dates to the 12th century and is unique in terms of architecture, as there is no other church in mainland Greece that belongs to the "island" simple octagonal type. The church is one-room with a square plan and was covered with a dome, which was replaced by a low shield after its collapse. Inside, the church preserves excellent frescoes of the 12th and 18th centuries. Remains of an early Christian church and remains of the Byzantine Monastery of Hortaitou are preserved in the surrounding area.