Thekkady (Idukki District) is the location of the Periyar National Park, which is an important tourist attraction in Kerala state, India, close to the Kerala -Tamil Nadu border town Kumily, located about 257 km (160 miles) from Trivandrum. The sanctuary is famous for its dense evergreen, semievergreen, moist deciduous forests and savannah grass lands. It is home to herds of elephants, sambar, tigers, gaur, lion-tailed macaques and Nilgiri langurs. The Periyar Wild Life Sanctuary was declared a Tiger Reserve in 1978. The splendid artificial lake formed by the Mullaperiyar Dam across the Periyar River adds to the charm of the park. The greatest attraction of Periyar are the herds of wild elephants that come down to play in the lake.