Kotor has one of the best preserved medieval old towns in the Adriatic and is a UNESCO world heritage site. It is home to numerous sights, such as the Cathedral of Saint Tryphon in the old town (built in 1166), and the ancient walls which stretch for 4.5 km (3 mi) directly above the city. Sveti Đorđe and Gospa od Škrpijela islets off the coast of Perast are also among the more popular destinations in the vicinity of Kotor.