The Silent Valley National Park is is located in the Nilgiri Hills, Palakkad District, Kerala.  It has an an area of nearly 90 sq km.  The Silent Valley National Park is also locally known as Sairndhrivanam, which means Sairandhri's Forest or forest in the valley.  Silent Valley is home to the largest population of lion tailed Macaque, an endangered species.  Establishment of Silent Vall ...