Fort St. George
Chennai, India
Fort St. George (or historically, White Town) is a fortress at the coastal city of Chennai, India. Founded in 1639, it was the first English (later British) fortress in India. The construction of the fort provided the impetus for further settlements and trading activity, in what was originally an uninhabited land. Thus, it is a feasible contention to say that the city (named Madras since before the arrival of the Europeans until July 1996) evolved around the fortress. The fort currently houses the Tamil Nadu legislative assembly and other official buildings.
Fort data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).