The Thar Desert is a large, arid region in the northwestern part of the Indian subcontinent and forms a natural boundary running along the border between India and Pakistan. With an area of more than 200,000 km2 (77,000 sq mi), it is the world's 9th largest subtropical desert.
It lies mostly in the Indian State of Rajasthan, and extends into the southern portion of Haryana and Punjab states and into northern Gujarat state. In Pakistan, the desert covers eastern Sindh province and the southeastern portion of Pakistan's Punjab province. The Cholistan Desert adjoins the Thar desert spreading into Pakistani Punjab province.