Birdwatching

This is what puts Gajoldoba on the map. The backwaters attract an astonishing variety of species. Besides the headline acts (Bar-headed Geese, Ruddy Shelducks), watch for Asian Openbills, common teals, northern pintails, gadwalls, and various kingfisher species. 

Pakhibitan Wildlife Sanctuary is located near Gajoldoba Teesta Barrage and is visited by thousands of bird enthusiasts every year. Keep an eye out not just for waterbirds but for raptors like the Marsh Harrier.
Bring quality binoculars, a field guide to Indian birds, patience, and if you're serious, a telephoto lens. Download bird identification apps before you arrive as internet can be patchy.