The southern most range of Himalayas is known as Siwalik. The Himadri and Himachal ranges of the Himalayas have been formed much before the formation of Siwalik range. The rivers rising in the Himadri and Himachal ranges brought gravel, sand and mud along with them, which was deposited in the rapidly shrinking Tethys Sea.
It is located southwards of Himadri. The breadth of Himachal range is 60 to 80 km and the height varies from 1000 metres to 4500 metres. Some of the peaks of this range have a height of more than 5000 metres. This range is highly dissected and uneven.
This is the highest mountain range of the world. It extends in the shape of an arc for a distance of about 2500 km from west to east along the northern boundary of India between the Indus gorge in Jammu and Kashmir in the west and Brahmputra gorge in Arunachal Pradesh in the east.
India is a land of physical diversities. Almost all types of picturesque and breath taking landforms are found here. According to one estimate, 29.3 per cent of area of India is occupied by mountains and hills, 27.7 per cent by plateaus and 43 per cent by plains.
A huge landmass of South Asia is flanked by new fold towering mountains on the northwest, north and northeast. The Arabian sea lies to its southwest, the Bay of Bengal to its southeast and the Indian Ocean to its south. This well defined South Asian landmass is called Indian sub-continent.