Charles Fort is a classic example of a late 17th-century star-shaped fort. William Robinson, the architect of the Royal Hospital in Kilmainham, Dublin, and Superintendent of Fortifications, is credited with designing the fort. As one of the largest military installations in the country, Charles Fort has been associated with some of the most momentous events in Irish history. The OPW offers free access to all OPW managed Heritage Sites to school-going children under their Free Schools Visits program. This Programme is intended to support the educational curriculum.