The Burlington County Prison Museum, a National Historical Landmark in the heart of historic Mount Holly, New Jersey, occupies the Burlington County Prison, which was designed by Robert Mills, one of America's first native-born and trained architects, and completed in 1811. As one of Mills' first independent architectural designs, it used interior vaulted ceilings of poured concrete and brick and stone construction to make the building virtually fireproof. The structure was well suited to its purpose, virtually maintenance free, and incorporated philosophies of penal reform advocated during the period through innovative interior planning, fireproofing, heating, and ventilation systems. It also reflected growing awareness of the social responsibility to rehabilitate criminals. So well constructed, it remained in constant use until 1965, and its exterior, including the massive front door with its large hinges and lock, has changed very little since it was built.