Situated in Eastern part of the country, Koshi Tappu Wildlife Resort covers 175sq.kms and it was established in 1976.
Rapid and complete inundation of the reserve to depth ranging from 10 to 300cms occurs during the monsoon. The Sapta -Koshi river also changes its courser from one season to another. The vegetation is mainly tall Khar -patter grassland with a few patches of Khair -sisso, scrub forest and deciduous mixed reverie forest.

The reserve offers important habitat for variety of wildlife. The last surviving population (about 10individuals) of Wild buffalo is found here. Other mammal's occurring here are hog deer, wild deer, spotted deer and blue bull.

This reserve is one of the best habitats for bird in Asia (probably in the world). A Total of 280 different species of birds have been recorded here. These include 20 species of ducks, 2 species of ibises, many storks, egrets, herons and the endangered swamp partridges and the Bengal Floricans. In the winter bird as far as from Siberia and Tibet come to stay in this reserve So if you are looking for bird watching tour this may be the best option in entire Asia . That's why the reserve is called he bird watcher's paradise.

A trip to Koshi is best for at least 3 nights and from 3 nights it will be better to have as many times as you can manage to get into the deep grassland to view rare species of birds and animals.