Koshi Tappu wildlife reserve (175sq km) is set in the flood plain of the Koshi River in the eastern Terai and is a haven for birds and bird lovers. There are more than 280 species of birds in the reverse and it is also a resting place for migrating birds that can't be seen elsewhere in Nepal. Mammals that abound here include the wild water buffalo (arna), wild bear, spotted deer and the blue bull. Koshi Tappu Wildlife Reserve can be reached by the East-West High way which runs alongside it.