What to isolate india from the rest of asia? what did this isolation cause?

India’s geography contributed to its isolation from the rest of Asia. It is a peninsula but on the North, the Himalayas shields it from invasion of both men and ideas. On the East there are dense forests that although have lower height, is infested with malaria. Great oceans surround the south and mountain ranges that are difficult to traverse block the West. As a result, the Indian community developed its caste system, the most elaborate expression in history of an unmoving agricultural society.