Lahugala National Park lies in the basin of the Heda Oya,16km inland from the coastal town of Pottuvil in Eastern province. The Pottuvil to Monaragala trunk road runs through the south eastern sector of the park. 6 53’- 6 55’N, 81 40’-8142’E. It was officially created as a national park on 31 October 1980 after having originally been established as a sanctuary on 1 July 1966.
The terrain is flat with occasional rock outcrops. The park features three tanks, Lahugala (243 ha) , Kitulana and Senagamuwa, which ultimately drain in to the Heda Oya. These tanks are largely silted up and support an abundance of beru grass. Mean annual rainfall is 1650 mm (McKay, 1973). There are two dry periods: from May to October and from mid-January to March . The northeast monsoon lasts from November to the end of December (Banks and Banks, 1985).
Lying in the dry zone, the vegetation surrounding the tank is dry mixed evergreen forest with scrub. Common species include weera Drypetes sepiaria, palu Manilkara hexandra, halmilla Berrya cordifolia, milla Vitex pinnata, satin Chloroxylon swietenia and ehala Cassia fistula. Beru Sacciopelsis interrupta, a tall reedy grass, covers the tanks. Rivers are fringed by gallery forest.