On the peninsula stands Alanya Castle, a Seljuk era citadel dating from 1226. Most major landmarks in the city are found inside and around the castle. The current castle was built over existing fortifications and served the double purpose of a palace of local government and as a defensive structure in case of attack. In 2007, the city began renovating various sections of the castle area, including adapting a Byzantine church for use as a Christian community center. Inside the castle is the Süleymaniye mosque and caravanserai, built by Suleiman the Magnificent. The old city walls surround much of the eastern peninsula, and can be walked. Inside the walls are numerous historic villas, well preserved examples of the classical period of Ottoman architecture, most built in the early 19th century.