BARTAN, a town in Asiatic Turkey, situated near the mouth of the Bartan-su, which was known to the Greeks as the Γarthenius, and formed part of the boundary between Bithynia and Paphlagonia. The town is built on two low limestone hills, and has its streets paved with blocks of that material. It carries on a considerable trade with Constantinople, which might be increased were it not for the obstruction of the harbour by a bar. Population between six and seven thousand.