Asansol is the largest city at Paschim Bardhaman district in the Indian state of West Bengal. It is the 2nd largest city in West Bengal after Kolkata and the district headquarters of Paschim Bardhaman district. It is the 39th largest urban agglomeration in India. According to a 2010 report released by the International Institute for Environment and Development, a UK-based policy research non-governmental body, Asansol was ranked 11th among Indian cities and 42nd in the world in its list of 100 fastest-growing cities. Area of this metropolitan city is 326.48 km2 (126.05 sq mi).