Dhanbad (Hindi: धनबाद) is a city in the state of Jharkhand, and is also known as the 'Coal Capital of India'. Dhanbad is among the top 79th fastest growing cities of world. According to 2001 census, Dhanbad is among the 35 cities of India with population more than one million.[2] Among the Rail Divisions of Indian Railway, Dhanbad Rail Division is in second position in terms of revenue generation. Dhanbad is famous for coal mining. Tata Steel, BCCL, ECL and IISCO are some of the companies having coal mines in the district. Coal-mining, Coal washing and coke making are the main coal related industries in the city. IISCO (Indian Iron And Steel Company) is now owned by SAIL, BCCL & ECL comes under CIL (Coal India Ltd), these two companies are the largest operators of coal mines in Dhanbad, and have open cast mines as well as underground mines, whereas Tata Steel has mostly underground mines. These companies have developed townships for their employees.