The largest town in Ladakh is Leh, followed by Kargil, each of which headquarters a district. The Leh district contains the Indus, Shyok and Nubra river valleys. The Kargil district contains the Suru, Dras and Zanskar river valleys. The main populated regions are the river valleys, but the mountain slopes also support the pastoral Changpa nomads. The main religious groups in the region are Muslims (mainly Shia) (46%), Tibetan Buddhists (40%), Hindus (12%) and others (2%). Ladakh is one of the most sparsely populated regions in India. As its culture and history are closely related to that of Tibet, it is known as the "Little Tibet".