The Southern Peninsula is mostly a raised table and of old, stable structure generally known as Deccan Plateau. Peninsular Plateau is marked off from the Indo-Ganga Plains by a mass of mountains and hill ranges. Aravalli, Vindhya, Satpura, Maikala and Ajanta are the main mountains of this range. 

The western and north western parts of the plateau extend into Kutch in Gujarat and the Aravalli range in Rajasthan. Its northern limits run parallel to and fifty miles south of the course of Ganga-Yamuna Rivers. The Peninsula is flanked on the one side by the Eastern Ghats and on the other by the Western Ghats or Sahyadri Mountains. 

Between the Western Ghats and the Arabian Sea lies a narrow coastal strip, while between Eastern Ghats and Bay of Bengal there is a border coastal area. In the south of the Peninsula where the two coastal ranges appear to merge, are two high granite massifs, the Nilgiri Hills and the Cardamom Hills. 

Geologically the Deccan Plateau is the oldest part of the Indian Subcontinent, a shield of old stable rocks. Most of India’s mineral wealth is found in the Deccan Plateau.