Angammedilla National park was established in June 2006 with the main purpose of protecting the drainage basin of Parakrama Samudra, located 225km away from Colombo in the Polonnaruwa district. It also secures the drainage basins of two irrigation tanks – Minneriya and Girithale Sanctuary, as well as the water sources in Sudu Kanda and the habitats of the wildlife in nearby forests. The southern part of the park is bordered by the Amban River, from which, as per ancient history records, water was irrigated to Parakrama Samudra via a stone canal.

A range of mountains span across the park from Girithale to Minneriya, receiving most of the rain during the rainy season than the plains. Since the park’s climate is a blend of both wet and dry, the vegetation of the park is a mix of wet and dry zone plants; dominated by dry evergreen forests and Mesua ferrea trees. Apart from the endemic animals such as elephants, deers, buffalos and peacocks, leopards and sloth bears can be seen occasionally too. Frequenting primates include the red slender loris, tufted gray and purple-faced langurs.