Fort William, officially Vijay Durg, is a fort in Hastings, Calcutta (Kolkata). It was built during the early years of Britain's administration of Bengal. It sits on the eastern banks of the River Hooghly, the major distributary of the River Ganga. One of Kolkata's most enduring British-era military fortifications, other than those in Bombay (Mumbai) and Madras (Chennai), it extends over an area of seventy hectares.
The fort was named after King William III. In front of the Fort is the Maidan, the largest park in the country. An internal guard room became the Black Hole of Calcutta. Today the fort is the headquarters of Eastern Command of the Indian Army.