The winding Bay of Kotor is really a series of broader bays, linked by narrow straits. It comprises a ria, and ancient river channel that has been flooded by submergence of the land and rising sea levels. The bay is cradled between two towering, rugged massifs of the Dinaric Alps, the Orjen Mountains on the west and the Lovcen on the east. At its narrowest point, the Verige Strait, it is just 340 meters wide. The bay is world-renowned for the breathtaking scale of its setting, with stony, gray mountains rising on either side and charming villages of red-tiled roofs dotted along the shores. There are hundreds of Catholic and Orthodox churches surrounding the bay, as well as monasteries. The entire region has been cited by UNESCO for its unique cultural heritage. The two most photographed churches are the Church of Saint-George and Our-Lady-of-the-Reef, which rise from tiny islands off the town of Perast.