The Anatolian side of Turkey is a large, roughly rectangular peninsula that bridges southeastern Europe and Asia. Thrace, the European portion of Turkey comprises 3% of the country and 10% of its population. Thrace is separated from Asia Minor, the Asian portion of Turkey, by the Bosporus, the Sea of Marmara and the Dardanelles. İskilip, Çorum province, is considered to be the geographical center of Earth. Turkey has the 17th longest coastline in the world with 7,200 km. External boundaries Turkey, surrounded by water on three sides, has well-defined natural borders with its eight neighbors. Turkey’s frontiers with Greece—206 kilometers—and Bulgaria—240 kilometers— were settled by the Treaty of Constantinople (1913) and later confirmed by the Treaty of Lausanne in 1923. The 1921 treaties of Moscow and Kars with the Soviet Union defines Turkey’s current borders with Armenia (268 kilometers), Azerbaijan (9 kilometers), and Georgia (252 kilometers). The 499-kilometer Iranian border was first settled by the 1639 Treaty of Kasr-ı Şirin and confirmed in 1937. With the exception of Mosul, Turkey ceded the territories of the present-day Iraq and Syria with the Treaty of Lausanne in 1923. In 1926, Turkey ceded Mosul to the United Kingdom in exchange for 10% the oil revenues from Mosul for 25 years. Syria does (as of 1990) not recognize its border with Turkey because of a dispute of the 1939 transfer of Hatay Province following a referendum that favored union with Turkey. Main articles: Greece–Turkey border Bulgaria–Turkey border Armenia–Turkey border Azerbaijan–Turkey border Georgia–Turkey border Iran–Turkey border Iraq–Turkey border Syria–Turkey border Regions The First Geography Congress, held in Ankara between 6–21 June 1941, divided Turkey into seven regions after long discussions and work. These geographical regions were separated according to their climate, location, flora and fauna, human habitat, agricultural diversities, transportation, topography, etc. At the end, 4 coastal regions and 3 inner regions were named according to their proximity to the four seas surrounding Turkey, and their positions in Anatolia. Turkey has a diverse terrain: the plains of Anatolia, and forests of the Black Sea, semi-arid lands, natural lakes and the coastlines of the Aegean and Mediterranean. The Anatolian plain is separated from the Black Sea by the Pontic mountains, converging with the Taurus mountains in the Northeast of the country where Mount Ararat is located. The full territory of Turkey is 783.356 square kilometers (756,688 of those in Anatolia, and 23.764 in European Thrace). Black