Sinharaja is a great location for general wildlife enthusiasts and one of the least disturbed and biologically unique primary lowland rain forests in Sri Lanka, covering an extent of over 11000 hectares. Of international significance and declared a Man and Biosphere Reserve (MAB) in 1978 when UNESCO included it in its international network of Biosphere reserves. It was subsequently designated a National wilderness area in 1988 and received full status as a UNESCO World Heritage Site in 1989.

Situated in the lowland wet zone of the country with an average temperature of 23.6C and an annual rainfall of more than 2500mm the high level of endemism makes it an international rarity. More than 60% of the trees are endemic and it is home to over 50% of Sri Lanka's endemic species of mammals and butterflies, as well as many kinds of insects, reptiles and rare amphibians. Of Sri Lanka's endemic birds, all 22 rainforest species are seen here, including the elusive Red-faced Malkoha, Green-billed Coucal and Sri Lanka Blue Magpie.

Due to the dense forest mammal life can be more difficult to spot, of the 40 species listed as being in the forest there is a good chance of seeing giant squirrels, mongoose, purple-faced langur, wild boar and barking deer.