'mithun' horns line the wall of an 'Adi' household.Arunachal Pradesh shares frontiers with China in the north and northeast, Myanmar in the east and Bhutan in the west. Assam and Nagaland form its southern and south-eastern boundaries. It is recognized as one of only 18 biodiversity hotspots around the world. Its nearly 85,000 square kilometres area forms a complex network of mountain ecosystems with deep valleys and high mountains. The Mithun is the domesticated version of the Himalayan Gaur and in NE India is used for agriculture and is considered a sign of wealth. It is also used in sacrificial offerings.