T HE SILENT VALLEY National Park, spread over an area of 90 sq km (35 sq miles), preserves what is perhaps the country’s last substantial stretch of virgin tropical evergreen forest. An important part of the Nilgiri Biosphere Reserve it represents some of the spectacular biodiversity of the Western Ghats. The park is renowned for its rare plants and herbs, which include over 100 species of orchids. Wildlife includes tigers, elephants, the Nilgiri langur, the sloth bear, the shy nocturnal slender loris, and the endangered lion-tailed macaque. A variety of birds, as well as a remarkable 100 species of butterflies and 400 species of moths, are also found here. Visitors can trek to the source of the Kunthipuzha river which flows through this valley. Accommodation is available at the forest lodge in Mukkali, just outside the park.