North India refers to a set of states in the non-peninsular region of the Republic of India including the area to the north of the Vindhya mountains, Narmada River and Mahanadi River, but excluding the states of Gujarat and Maharashtra in the west, West Bengal and Orissa in the east as well as the seven North-East states. New Delhi, the capital of India lies in North India. The dominant geographical features of northern India are the Indo-Gangetic Plain whose fertile soils and perennial rivers have sustained large populations and the Himalayas which cut the region off from the rest of Asia. North India has been the historical center of the Maurya, Gupta, Mughal and British Indian Empires. It has a rich and diverse culture, having the Hindu holy cities of Varanasi and Allahabad along with world heritage sites representing Islam and Buddhism within its boundaries.The Eastern parts of this region continues to face problems of overpopulation, poverty, illiteracy despite significant economic growth and the Green Revolution.