Lop Nur (lôp nûr) [key], salt basin, SE Xinjiang Uygur Autonomous Region, China, in the Tarim River basin. Since 1964, Lop Nur has been used by the China for its nuclear test explosions. Once a large salt lake (as mapped by ancient Chinese geographers), it is now largely dried up, with marshes and small, shifting lakes receiving the channels of the Tarim river. The region was explored by N. M. Przhevalsky and Sven Hedin; archaeological sites at the ancient margins of the lake have yielded mummies of Caucasian inhabitants. In 1928, at the time of the last expedition, the lake covered c.1,200 sq mi (3,100 sq km). The name sometimes appears as Lop Nor and Lo-pu po.