Nongkhyllem Sanctuary is one of the very renowned wildlife sanctuaries in the north east.The area consist of undulating plain to low hills. This hilly park drained by many rivers like Umtrew, Umran, Umling, Umtasor, and other smaller streams. The area lies below 1,000m above msl, it falls in Biome-9 (Indo-Chinese Tropical Moist Forest) resulted tropical monsoon climate. The summer are hot and wet while winters are cool and dry.
Area: 29 sq. km
Altitude: 200 to 950 m above msl
Rainfall: 2,000 to 3,200 mm
Temperature: 5˚C to 35˚C
Best time to visit: October to April
Vegetation: Tropical semi-evergreen forest, Tropical Moist Deciduos Forest, and Montane Grassy Land.
Mammals: The sanctuary supports various species of fauna including those facing the danger of extinction. They include Royal Bengal Tiger, Indian Bison, Himalayan Blcak Bear, Clouded Leopard, etc. The park also save home of Wild Asian Elephants including Leopard, Leopard cat, Jungle cat, Fishing cat, Wild Dog, Sloth Bear, Hoolock Gibbon, Slow Loris, Capped Langur, Sambar, Gaur, Binturang, Malayan Giant Squirrel etc.
Birds: The two winged birds that dwell here are valued to watch, it is a perfect place for the birdwatchers.The most common bird species you can spot while exploring in the forest are the Rufous Necked Hornbill, Manipur Bush Quail, Brown Hornbill, and many more.White-cheeked Partridge, Grey Peacock Pheasant, Pale-headed Woodpecker, Black back forktail, Lesser Neckleced, Greater Neckleced and Rufous-Neckleced Laughingthrush, Suntan tit, Sapphire Flycatcher, Rufous-bellied Niltava, Bay woodpecker, Rosy Minivet, Short billed Minivet, Striated Bulbul, White Throated bulbul, Orange bellied Leafbird, Slaty-billied Tesia, Maroon Oriol, Lesser Grey headed Fish Eagle etc.