The Sinharaja Rain Forest is one of the least disturbed and biologically unique lowland rain forests now remaining in Sri Lanka. It covers an area of approximately 12,000 hectares and its elevation ranges from 200m to 1300m above sea level. The vegetation of the forest may be described either as a Tropical Lowland Forest or Tropical Wet Evergreen Forest .Out of 211 woody trees 139 are endemic, and out of 25 endemic ferns and epiphytes as well, 13 are represented in Sinharaja.

Preliminary studies on the fauna have revealed that, there is a high degree of endemism among butterflies, fish, amphibians, reptiles, birds, and mammals. In fact 95% of the endemic birds of Sri Lanka are recorded in Sinharaja. The rarest endemic birds to be seen are the red-faced Malkoha , Sri Lanka blue Magpie, the Ashy-headed Babbler, the White-headed Starling and the Green-billed Coucal.