The lands of Turkey are located at a point where the three continents making up the old world, Asia, Africa and Europe are closest to each other. Turkey is situated on an area where Europe meets Asia, creating a link between these two continents. The European part of the country is called Thrace, while the Asian part is known as Anatolia (or Asia Minor). It is bordered to the northwest by Greece and Bulgaria, to the east by the former USSR (Georgia, Armenia, and Azerbaijan Republics) and Iran, and to the south by Iraq and Syria. The Turkish peninsula is bathed by four seas: the Mediterranean to the south, the Aegean to the west, the Sea of Marmara between the European and Asian land masses, and the Black Sea to the north. The entire coastline spans more than 8,000 kilometers (approximately 5,000 miles ) in length. Because of its geographical location the mainland of Anatolia has always found favour throughout history, and is the birthplace of many great civilizations. It has also been prominent as a center of commerce because of its land connections to three continents and the sea surrounding it on four sides. Although Turkey is situated in a geographical location where climatic conditions are quite temperate, the diverse nature of the landscape, and the existence in particular of the mountains that run parallel to the coasts, results in significant differences in climatic conditions from one region to the other. While the coastal areas enjoy milder climates, the inland Anatolian plateau experiences extremes of hot summers and cold winters with limited rainfall.