The Ganga is the longest river originating in India. The Ganga-Brahmaputra system occupies most of northern, central, and eastern India, while the Deccan Plateau occupies most of southern India. Kangchenjunga, in the Indian state of Sikkim, is the highest point in India at and the world's third highest peak.The climate across India ranges from equatorial in the far south, to alpine and tundra in the upper regions of the Himalayas.