The Ngiyampaa people, also spelt Ngyiyambaa, Nyammba and Ngemba, are an Aboriginal Australian people of the state of New South Wales. The generic name refers to an aggregation of three groups, the Ngiyampaa, the Ngiyampaa Wangaaypuwan, and the Ngiyampaa Wayilwan, respectively clans of a larger Ngiyampaa nation.
The Muthi Muthi people are an indigenous Australian people whose traditional lands are located in the Northern Riverina and Far West regions of New South Wales.
The Muthi Muthi are the traditional owners of Nimmie Caira and the Lowbidgee and share custodial rights for Lake Mungo, Mungo Man and Mungo Lady with the neighbouring Paakantji and Ngiyampaa groups.
The Willandra Lakes Region is a World Heritage Site in the Far West region of New South Wales, Australia. The Willandra Lakes Region is the traditional meeting place of the Muthi Muthi, Ngiyampaa and Paakantyi Aboriginal peoples. The 2,400-square-kilometre (930 sq mi) area was inscribed on the World Heritage List at the 5th Session of the World Heritage Committee in 1981.
The Region contains important natural and cultural features including exceptional examples of past human civilization including the world's oldest evidence of cremation. A small section of the region is protected by the Mungo National Park.