Finished in 1653 by the British East India Company, the fort has undergone many facelifts over the years. Inside the vast perimeter walls is now a precinct housing Tamil Nadu's Legislative Assembly & Secretariat, and a smattering of older buildings. One of these, the Fort Museum, has displays on Chennai's origins and the fort itself, and interesting military memorabilia and artwork from colonial times. The 1st-floor portrait gallery of colonial-era VIPs includes a very assured-looking Robert Clive (Clive of India).

Also within the fort is St Mary's Church, completed in 1680, and India's oldest surviving British church. To its right is the former Admiralty House (Clive's House). Clive's Corner, at the end of the building, houses a quirky memorial museum to Robert Clive.