Canyons are those types of gorges where strata involved in down cutting is essentially horizontal or nearly so. The Grand Canyon of Colorado is a well-known example.

The mountains considered under tectonic mountains are volcanic mountains, fault block mountains and folded mountains. Residual mountains are totally belonging to a different class of mountains.

Tectonic lake basins are commonly rectangular in outline and semi-permanent in nature.

A river valley is result of down-cutting and bank erosion by river. Since most of river erosion processes are concentrated along bottom of a river channel, especially in mountainous regions, resulting river valley has a typical V-shaped cross-section.

Exceptionally deep saw cut valleys with slightly opened up tops indicating some denudation are specially referred to as Gorges. These are quite common and impressive features of major Himalayas Rivers in ir mountainous tracts.

In geological sense, term mountain refers to a continuous belt or zone of rocks that has suffered complex deformations (Like folding and faulting) through geological ages. These may or may not be having high relief at present.

The Wular Lake of Kashmir is fresh water; it receives river Jhelum at one end which drains out from or end near Baramullah.

Many highlands on Peninsular India are in reality residual in nature representing parts of rocks exposed to erosive work for millions of years.

Craters of extinct volcanoes are excellent depressions to serve as lake basins. Volcano created basins are commonly circular in outline.

Mountains resulting from depression or elevation of blocks of Earth crust on a large scale due to faulting; se elevated structures are commonly called fault block mountains.