South Asia or Southern Asia is the southern region of Asia, comprising the sub-Himalayan countries and, for some authorities, the adjoining countries to the west and the east. Topographically, it is dominated by the Indian Plate, which rises above sea level as the Indian subcontinent south of the Himalayas and the Hindu Kush. South Asia is bounded on the south by the Indian Ocean and on land (clockwise, from west) by West Asia, Central Asia, East Asia, and Southeast Asia.
According to the United Nations geoscheme,Southern Asia comprises the countries of Afghanistan, Bangladesh, Bhutan, India, Iran, Maldives, Nepal, Pakistan, and Sri Lanka. Burma and Tibet are also sometimes included in the region. South Asia is home to well over one fifth of the world's population, making it both the most populous and most densely populated geographical region in the world The South Asian Association for Regional Cooperation is an economic cooperation organization in the region.