 Major peaks in the sanctuary are Karimala Gopuram (1438 m) in the southern boundary of the sanctuary, Pandaravarai (1290 m) in the north, Kuchimudi, Vengoli Malai (1120 m) in the eastern boundary and Puliyarapadam (1010 m) in the west.The sanctuary has three man-made reservoirs; Parambikulam, Thunacadavu (Thunakkadavu) and Peruvaripallam, with a combined area of 20.66 km2.The Thuvaiar water falls empty into one of the reservoirs.