Repetek Biosphere State Reserve, often referred to as Repetek Nature or Desert Reserve, (Turkmen: Repetek goraghanasy) is a desert nature reserve (zapovednik) of Turkmenistan, located in Lebap Province, East Karakum Desert, near Amu Darya. It is located approximately 70 km (43 mi) south from Türkmenabat and is known for its zemzen (desert monitor which is Varanus griseus). Established in 1928 for the study and preservation of a sand-desert ecosystem, it covers an area of 346 km2 (134 sq mi).