Bustling Trabzon is a large harbor city enclosed by the soaring peaks of the Eastern Pontiac Mountains, which run along the coast. It was founded perhaps as early as the 8th century BC by Greek settlers and soon flourished as part of the caravan trade route between Persia and the Mediterranean. The main tourist attraction is the Aya Sofya Museum (Hagia Sophia Church), probably built by Emperor Alexius Comnenus immediately after his arrival in Trabzon from Constantinople (modern Istanbul) in 1204. It was converted into a mosque in Ottoman times and is now a museum. The church follows a cruciform plan, with a nave flanked by aisles and a transept with frescoes. Along the base of the south doorway is a frieze depicting the story of Adam in a style showing a clear Eastern influence. Despite the fact the wall paintings are severely defaced, they are still beautiful.