protectorate of the United Kingdom, which ceded it to Greece in 1947 following the Paris peace treaty. Geology The island is part of a chain of mountains from which it became separated after earthquakes and subsidence that occurred in ancient times. The remnants of these mountains include the islands of Kalymnos and Kappari which are separated by an underwater chasm approximately deep, as well as the volcano of Nisyros and the surrounding islands. There is a wide variety of rocks in Kos which is related to its geographical formation. Prominent among these are the Quaternary layers in which the fossil remains of mammals such as horses, hippopotami and elephants have been found. The fossilised molar of an elephant of gigantic proportions was presented to the Paleontology Museum of the University of Athens. Demographics Turkish population In the late 1920s about 3,700 Turks lived in Kos city, slightly less than 50% of the population, who were mainly in the west part of the city. Today, the population of the Turkish community in Kos has been estimated at about 2,000 people. A village with significant Turkish population is Platani (Kermentes) near the town of Kos. Religion The people of Kos are predominantly Orthodox Christians – one of the four Orthodox cathedrals in the Dodecanese is located in Kos. In addition, there is a Roman Catholic church on the island and a mosque for the Turkish Muslim community. The synagogue is no longer used for religious ceremonies as the Jewish community of Kos was targeted and destroyed by occupying German forces in World War II. It has, however, been restored and is maintained with all religious symbols intact and is now used by the Municipality of Kos for various events, mainly cultural. Main sights Castles The island has a 14th-century fortress at the entrance to its harbour, erected in 1315 by the Knights Hospitaller, and another from the Byzantine period in Antimachia. Ancient Agora The ancient market place of Kos was considered one of the biggest in the ancient world. It was the commercial and commanding centre at the heart of the ancient city. It was organized around a spacious rectangular yard wide and long. It began in the Northern area and ended up south on the central road (Decumanus) which went through the city. The northern side connected to the city wall towards the entrance to the harbour. Here there was a