A landmass which is separated from the rest of the continent by water bodies or mountains is called a subcontinent. India is called a subcontinent because of its : (a) Vast size, (b) diversity, (c) the ice-covered lofty Himalayas in the North, (d) the vast Indo-Ganga plain to its south, (e) the Thar desert, (f) the uneven Deccan plateau, (g) the high temperature and heavy rainfall . from the tropical monsoon climate.