Ganges plain occupy area in the states of Uttar Pradesh, West Bengal, Jharkhand and Bihar. Among the largest cities of the Indo-Gangetic plain are Karachi, Hyderabad, Multan, Islamabad, Rawalpindi, Faisalabad, Lahore, Amritsar, Ludhiana, Chandigarh, Delhi, Jaipur, Kanpur, Lucknow, Allahabad, Varanasi, Patna, Kolkata, Guwahati and Dhaka. In this region, it is hard to define where one megalopolis begins and one ends.