Asia is the Earth’s largest and most populous continent, located primarily in the eastern and northern hemispheres. This continent covers an area of 44,579,000 square kilometers, about 30% of Earth’s total land area and 8.7% of the Earth’s total surface area. It has historically been home to the world’s first modern civilizations and has always hosted the bulk of the planet’s human population. Asia is notable for not only its overall large size and population, but unusually dense and large settlements as well as vast barely populated regions within the continent of 4.4 billion people. The boundaries of Asia are traditionally determined as that of Eurasia, as there is no significant geographical separation between Asia and Europe. The most commonly accepted boundaries place Asia to the east of the Suez Canal, the Ural River, and the Ural Mountains, and south of the Caucasus Mountains 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.