Sinharaja Forest Reserve is a forest reserve and a biodiversity hotspot in Sri Lanka. It is of international significance and has been designated a Biosphere Reserve and World Heritage Site by UNESCO.
According to International Union for Conservation of Nature (IUCN), Sinharaja Forest Reserve is the country’s last viable area of primary tropical rainforest. More than 60% of the trees are endemic and many of them are considered rare. 50% of Sri Lankan’s endemics species of animals (especially butterfly, amphibians, birds, snakes and fish species). It is home to 95% endemic birds.
The hilly virgin rainforest, part of the Sri Lanka lowland rain forests ecoregion, was saved from the worst of commercial logging by its inaccessibility, and was designated a World Biosphere Reserve in 1978 and a World Heritage Site in 1988.
The rainforest likely formed during the Jurassic period (from 200 million years to 145 million years ago). This forest encompasses an area of 36,000 hectares (88,960 acres/360 km²). The reserve is only 21 km (13 mi) from east to west, and a maximum of 7 km (4.3 mi) from north to south, but it is a treasure trove of endemic species, including trees, insects, amphibians, reptiles, birds, and mammals. Sinharaja forest vegetation density has been estimated at around 240,000 plants per hectare, the most dense rain forest in Asia.