Assam, is an ancient settlement. As the main airline center in the northeast, it is a convenient point of entry into the Brahmaputra Valley in which the state is cradled. Impressive in its immensity and enchanting in its beauty. "Umanda Temple" dedicated to Shiva, is on Peacock Island in the middle of the river. The "Navagarh Temple" on Chitrachal Hill near the city, was once a center for the study of astronomy and astrology. "Kamakshya Temple" on Milachal Hill, ten Kms from Guwahati and a center for Shakti worship, attracts pilgrims during the Ambuchi Festival in August. In the center of Guwahati, the "Janardan Temple" has an image of the Buddha Demonstrating how Buddhism was assimilated into Hinduism. Other places of interest in Guwahati are the "Assam State Zoo" and the "Assam State Museum". Northeastern India is rich in wildlife sanctuaries. Assam had nine in 1990, of which Manas and Kanziranga are the most famous. Kaziranga was established in 1908 and now cover 430 square Kms of forest, swamp and plains. There are wild elephants, wild buffaloes and swamp deer, hog deer , tigers and some exotic birds. Game viewing is mostly done from the back of an elephant. Manas, six hours north of Guwahati, now protects over 2,837 square Kms of sub Himalayan riverine forest on the south bank World Heritage Site and contains 21 of South Asia's most endangered mammal species and an extraordinary range of birds. Apart from Assam 's rivers, forest and animals, visitors can hardly miss the local tea industry. At harvest time, women with wicker baskets strapped to their heads wend their way through the bushes and pluck the leaves . India is the largest producer of tea in the world. Assam produces 60 percent of India's tea, over 50 percent of which is exported.