Sand dunes are usually found in Desert areas. In India, it can be found in the Thar Desert. Sand dunes are created when wind deposits sand on top of each other until a small mound starts to form. Once that first mound forms, sand piles up on the windward side more and more until the edge of the dune collapses under its own weight. The collapse begins when the angle of the dune becomes too large to support the weight.