The Nilgiri Biosphere Reserve is the first Biosphere reserve of India and is an International Biosphere Reserve in the Western Ghats and Nilgiri Hills ranges of South India. The Nilgiri Sub-Cluster is a part of the Western Ghats, which was declared a World Heritage Site by UNESCO in 2012. It includes the Aralam, Mudumalai, Mukurthi, Nagarhole, Bandipur and Silent Valley national parks, as well as the Wayanad and Sathyamangalam wildlife sanctuaries.
A fascinating ecosystem of the hill ranges of Nilgiris and its surrounding environments covering a tract of over 5000 square kilometers was constituted as Nilgiris Biosphere Reserve by UNESCO in September 1986 under Man and Biosphere Programme.