Home to a large number of plant and animal species, silent valley national park got its name due to the absence of the sound of crickets which is present in almost all forest ranges. The famous Kuntipuzha run through this national park and was the site for a hydroelectric power dam by Kerala state electricity board. After the strong agitations against the project by environmentalists and social activists the forest range was declared as National park  The core zone of the year 1984. It is believed that the forest area coming under this national park has un disturbed virgin lands un touched by humans. The Core zone of the national park has 236.74 square kilometres of dense forest range. Contiguous with the proposed Karimpuzha National Park (225 km²) to the north and Mukurthi National Park (78.46 km²) to the north-east, it is the core of the Nilgiri International Biosphere Reserve (1,455.4 km²), and is part of The Western Ghats World Heritage Site, Nilgiri Sub-Cluster (6,000+ km²) under consideration by UNESCO. The dense forest in the valley called 'Sairandhri Vanam' and the river Kunthi give a mythological dimension to the National Park. Vehicular transport is possible only up to Mukkali, nearly 24 kms from the park. The region is home to the rare Lion Tailed Macaque, Nilgiri Langur, Tigers, Leopards, Indian Bison, Elephants, Bears, Squirrels and a wide variety of deer. The breathtaking panoramic views of the valleys with silver cascades and perennial wild rivulets will stay etched in the minds of a visitor forever. Silent valley National Park located around 40 kms from Mannarkkad in the Palakkad district.