The Horton plain has rich vegetation, located 189 km away from Colombo. Before British period, it was Maha Eli Thenna “Great open plain” then the plain were renamed after Sir Robert Wilmot – Horton. Horton Plains, the coldest and windiest location in Sri Lanka consists of ecosystems such as Montana evergreen forests, grasslands, marshy lands and aquatic ecosystem. At an altitude of 2,100 meters above sea level, Horton Plains spreads across over 3,169 hectares of the highest tableland of the island. In view of the large number of endemic flora and fauna species, Horton Plains was declared a UNESCO World Heritage Site on 30th July 2010. The escarpment with a depth of 900 meters called World’s End and Baker’s Falls are the highlights of the Horton Plains and its surroundings, forests and the adjoining Peak Wilderness constitute Sri Lanka's most important catchment area of almost all major rivers. The plains are also of outstanding scenic beauty and conservation importance, containing most of the habitats and endemic plants and animals representative of the country's wet and Montana zones. Horton plain is purely destination for nature tourist.
The vegetation of the park is classified into two distinctive groups, 2,000 hectares of wet patana (Sinhalese for "Montanegrasslands") and 1,160 hectares of subtropical montage evergreen forestsNearly 750 species of plants belonging to 20 families have been recorded from the park. The forest canopy reaches the height of 20 meters (66 ft.) and features Calophyllumwalkeri, forming communities with varieties of Myrtaceaespecies. Species such as Gordonia and Rhododendron arboreum have spread to Sri Lanka, along the Western Ghats of South India from the Himalayas and are now common. Nearly 54 woody plant species have been recorded from the park, of which 27 (50%) are endemic to Sri Lanka.
The vertebrate fauna of the region include 24 species of mammals, 87 species of birds, nine species of reptiles and eight species of amphibians. The Sri Lankan Elephant disappeared from the region in the 1940s at the latest. At present, the largest and the most commonly seen mammal is the Sambar Deer. Other mammal species found in the park include Kelaart's Long-clawed Shrews, Toque Macaques, Purple-faced Langurs, Rusty-spotted Cat, Sri Lankan Leopards, Wild boars, Stripe-necked Mongooses, Sri Lankan Spotted Chevrotains, Indian Muntjacs, and Grizzled giant squirrels. Fishing Cats and European Otters visit the wetlands of the park to prey on aquatic animals.
Along with Ohiya, Pattipola and Ambewela, Horton Plains forms one of the Important Bird Areas in Sri Lanka.Sri Lanka bush warbler, Dull-Blue flycatcher, Sri Lanka whistling thrush and the yellow-eared bulbul, Sri Lanka Wood Pigeon, Sri Lanka White-eye, Spot-winged Thrush, Dull-blue Flycatcher, Sri Lanka Bush Warbler, Scaly Thrush, Sri Lanka Whistling Thrush, Brown-capped Babbler, Sri Lanka Spur-fowl and Sri Lanka Jungle-fowl. Other highlights are the Himalayan migrants Pied Thrush, Kashmir Flycatcher & Indian Pitta, Black Bird, Mountain Hawk Eagle, Black Eagle, Jerdon’sBaza, Pied Bushchat, Hill Swallow and Hill Munia.