This project was the structural and historical restoration of a 300-year old prison. This facility is listed on the State Historic Register, the National Historic Register, and is designated as a National Historic Landmark. It was originally North America’s first copper mine and later became a prison, which operated until after the Civil War.

The project included the air-conditioning of the mine shafts, an addition to the visitors’ center, the structural renovation of the tobacco shed, re-roofing and re-painting of Viets’ Tavern, structural underpinning of the Guard House, repointing stone walls, and numerous ramps for ADA accessibility. Special care was taken not to disturb the underground river.

The Prison is administered by the CT State Historic Commission.