South Asia is made up of three topographic regions. The Himalaya, Karakorum, and Hindu Kush mountain ranges and their southern slopes ,the Indo-Gangetic plain, and the Deccan plateau.
`The Himalaya, Karakorum, and Hindu Kush mountain ranges separate the South Asian subcontinent from the rest of Asia. The Himalayas, the highest mountains in the world, extend 1,500 miles west from the Brahmaputra River to the Karakorum, a mountain range that extends 300 miles and lies between the Indus River to its east and the Yarkand River to its west. The Hindu Kush, the world's second highest range, extends 500 miles west and south of the Yarkand River.
To the south of the mountain ranges is the 200 mile-wide Indo-Gangetic plain. The plain is a broad strip of low, relatively flat land lying between the Himalaya Mountains to the north and the Narmada and Mahanadi Rivers to the south. The Indus, Ganges, and Brahmaputra Rivers and their many tributaries have created this alluvial plain as they flow from the Himalayas to the sea. The Indus and its tributaries flow south and west to empty into the Arabian sea; the Ganges and Brahmaputra and their tributaries flow south and east to enter the Bay of Bengal.
To the south of the plain is the Deccan plateau, a relatively flat highland area that lies between the Western Ghat Mountains ranging from northwest to southeast and the Eastern Ghat Mountains ranging from northeast to southwest. The mountains separate the plateau from the coastline and meet in the south at the tip of the triangular-shaped peninsula known as Peninsular India.
Peninsular India juts out into the Indian Ocean.