Trabzon was founded in the 7th century B.C. by Milletain colonists. On entering the city, on a green hill descending to the sea, is a well-preserved 13th century Byzantine church, now the Avasofya Museum. The walls of this church are decorated with frescoes, some of the finest examples of Byzantine craftmanship. The higher part of the city, the old quarter, inside the still extant fortifications with its timber houses, should be visited.