Where was Fort St. George located?

NCERT (Pre-rationalised): “3.1 Ports, forts and centres for services … By the eighteenth century Madras, Calcutta and Bombay had become important ports. The settlements that came up here were convenient points for collecting goods. The English East India Company built its factories (i.e., mercantile offices) there and because of competition among the European companies, fortified these settlements for protection. In Madras, Fort St George, in Calcutta Fort William and in Bombay the Fort marked out the areas of British settlement. Indian merchants, artisans and other workers who had economic dealings with European merchants lived outside these forts in settlements of their own.…”