Gal Oya National Park, located 300 kilometres from Colombo in the Ampara and Badulla districts, derives its name from the Gal Oya, the river that flows through it. After Independence in 1948 this river was dammed in order to create the largest reservoir in the island, the Senanayake Samudra, which is 78 square kilometres in extent. It is possible to take boat trips on the Senanayake Samudra, which supports a sizeable fishing industry. This is a good way of seeing the rich aquatic bird life that frequents the reservoir.

This large body of water with its impressive backdrop of rocky, forested hills is considered to be one off the most attractive landscapes the island has to offer. When the “sea” was constructed, however, the waters submerged great tracts of forest, the home of the hunter-gatherer tribe of Veddhas. A few gnarled trunks sticking out of the water bear mute testament to the unfortunate side of this inundation. This body of water and its considerable catchment area comprise the Gal Oya National Park, which was established in 1954 and covers some 62,936 hectares.

Gal Oya is in essence a valley that is redolent of history. It has given refuge to several kings in the distant past. In the 2nd century BC, for instance, King Tissa sought refuge Digavapi, the place the Buddha is said to have visited on his third and last visit to Sri Lanka. The dagoba built to commemorate this event attracts thousands of pilgrims annually. Then in the 13th century, King Buvenekabahu sought refuge at the summit of Govindahela, a peak within the park. Henebedde cave near the mountain of Vadinagala has a drip ledge with Brahmi inscriptions, and nearby are a moonstone and guard stone.

Gal Oya National Park comprises forest and grassland. The forest is generally evergreen with a dense canopy. Predominant tree species are Halmilla or Trincomalee wood, etamba, kalumediriya or calamander and kaluwara or ebony. In the grasslands the main species are aralu (Terminalia chebula), bulu (Terminalia bellirica), and gammalu (Pterocarpus marsupium). A total of 32 species of mammal have been recorded at Gal Oya National Park. The most prevalent are the Sri Lanka grey languor, toque monkey, Sri Lanka leopard, Sri Lanka sloth bear, Sri Lanka elephant, Indian wild boar and water buffalo.

150 species have been recorded in the area. Most remarkable are the endemics, the red-faced malkoha (Phoenicophaus pyrrhocephalus) and Sri Lanka spur fowl. There are large numbers of fish eating birds, such as the little cormorant, great cormorant, Indian cormorant, spot-billed pelican, grey-headed fishing eagle, and white-bellied sea eagle. Reptiles include the Sri Lanka swamp crocodile - which is found in the water bodies and irrigation canals - and the water monitor - which is found in the drier areas. There are many snakes, such as the rat snake, python or pimbura (Python molurus), as well as the venomous cobra and Russell’s viper.