The Tibetan Plateau (Tibetan: བོད་ས་མཐོ།, Wylie: bod sa mtho), also known in China as the Qinghai–Tibet Plateau or the Qingzang Plateau (Chinese: 青藏高原; pinyin: Qīngzàng Gāoyuán) or Himalayan Plateau, is a vast elevated plateau in Central Asia or East Asia, covering most of the Tibet Autonomous Region and Qinghai Province in western China, as well as part of Ladakh in Jammu and Kashmir state of India. It stretches approximately 1,000 kilometres (620 mi) north to south and 2,500 kilometres (1,600 mi) east to west. With an average elevation exceeding 4,500 metres (14,800 ft), the Tibetan Plateau is sometimes called "the Roof of the World" and is the world's highest and largest plateau, with an area of 2,500,000 square kilometres (970,000 sq mi) (about five times the size of Metropolitan France). Sometimes termed the "Third Pole", the Tibetan Plateau is the headwaters of the drainage basins of most of the streams in surrounding regions. Its tens of thousands of glaciers and other geographical and ecological features serve as a "water tower" storing water and maintaining flow.