Residual mountains are those mountains which have been eroded by the agents of degradation such as winds, rain, frost and running water. The hard rocks that are left behind are called residual mountains.

The Sierras of central Spain and Mesas of USA are some examples of residual mountains. Examples of Residual Mountains in India are: the Aravali hi,lls, the Nallamala hills, the Javadi hills, the Veliconda hills, the Palkonda range, and the Mahendragiri hills.

Source: NCERT