Asia is the largest continent on Earth. It covers 8.7% of the Earth’s total surface area (or 30% of its land area). Asia is generally defined as comprising the eastern four-fifths of Eurasia. It is located to the east of the Suez Canal and the Ural Mountains, and south of the Caucasus Mountains (or the Kuma-Manych Depression) and the Caspian and Black Seas.  It is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean and on the north by the Arctic Ocean. Asia is subdivided into 48 countries, two of them (Russia and Turkey) having part of their land in Europe.