Hollongapar Gibbon Sanctuary which is also known as Gibbon Wildlife Sanctuary or Hollongapar Reserved Forest is the home of India's only primates the "Hoolock Gibbons" and also the “Bengal Slow Loris” which is the only nocturnal primatefound in Northeast India. Being a evergreen forest the Gibbon Wildlife Sanctuary is very rich in biodiversity in terms of both Flora and Fauna. The upper part of this forest is surrounded by Hollong trees which are the favorite food of Hoolock Gibbons. Apart from that 219 species of birds, several types of snakes and 211 types of butterflies are recorded here. . You can explore the park only by trekking, there are no roads here due to which jeep safari or elephant safari are not available.