Asia ( or ) is the
Earth's largest and most populous
continent, located primarily in the
eastern and
northern hemispheres. Asia 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 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.