The Silent Valley contains India’s last substantial stretch of tropical evergreen rain forests and it is perhaps the only vestige of a near virgin forest in the whole of the Western Ghats. Elephants, tigers, wild dog, flying squirrel and lion-tailed macaque are found here.

Vehicular traffic is allowed upto Mukkali from Mannarghat. From Mukkali one has to cover at least 24 km on foot to reach the source of river Kuntipuzha, which flows through the valley. Admission to this part is restricted. Prior permission is required to visit the part.