Fort Pontchartrain du Détroit or Fort Detroit (1701–1796) was a fort established on the north bank of the Detroit River by the French officer Antoine de la Mothe Cadillac and the Italian Alphonse de Tonty in 1701. In the 18th century, French colonial settlements developed on both sides of the river, based on the fur trade, missions, and farms. The site of the former fort, north of the Rouge River, is now within the city of Detroit in the U.S. state of Michigan, an area bounded by Larned Street, Griswold Street, Washington Blvd. and the Civic Center (now occupied by office towers).