Eastern Anatolia, where the Pontic and Anti-Taurus mountain ranges converge, is rugged country with higher elevations, a more severe climate, and greater precipitation than are found on the Anatolian Plateau. The western part of the Eastern Anatolia Region is known as the Anti-Taurus, where the average elevation of mountain peaks exceed 3,000 meters; while the eastern part of the region was historically known as the Armenian Highland and includes Mount Ararat, the highest point in Turkey at 5,137 meters. Many of the East Anatolian peaks apparently are recently extinct volcanoes, to judge from extensive green lava flows. Turkey's largest lake, Lake Van, is situated in the mountains at an elevation of 1,546 meters. The headwaters of three major rivers arise in the Anti-Taurus: the east-flowing Aras, which pours into the Caspian Sea; the south-flowing Euphrates; and the south-flowing Tigris, which eventually joins the Euphrates in Iraq before emptying into the Persian Gulf. Several small streams that empty into the Black Sea or landlocked Lake Van also originate in these mountains.