Sigur Plateau is a plateau in the north and east of Nilgiri District in the Nilgiri Hills of Tamil Nadu, South India. It covers the 778.8 square kilometres (300.7 sq mi) portion of the Moyar River drainage basin on the northern slopes of the Nilgiri Hills, south of the Moyar River.

Mudumalai National Park is a national park in the Nilgiri Mountains in Tamil Nadu in southern India. It covers 321 km2 (124 sq mi) at an elevation range of 850–1,250 m (2,790–4,100 ft) in the Nilgiri District and shares boundaries with the states of Karnataka and Kerala. A part of this area has been protected since 1940. The national park has been part of Nilgiri Biosphere Reserve since 1986 and was declared a tiger reserve together with a buffer zone of 367.59 km2 (141.93 sq mi) in 2007. It receives an annual rainfall of about 1,420 mm (56 in) and harbours tropical and subtropical moist broadleaf forests with 498 plant species, at least 266 bird species, 18 carnivore and 10 herbivore species. It is drained by the Moyar River and several tributaries, which harbour 38 fish species.