The largest plateau in the world is the Tibetan Plateau, also known as the Qinghai-Tibet Plateau. It covers approximately 2.5 million square kilometers (970,000 square miles) and has an average elevation of over 4,500 meters (about 14,800 feet) above sea level. This plateau is often referred to as the "Roof of the World" due to its vast size and extreme height, and it includes some of the world's highest mountain ranges such as the Himalayas. It is also the source of several major rivers in Asia.