One of a number of forts built in the 1850s and 1860s to protect Portsmouth and its vital harbour against a French invasion. Largely unaltered, the parade ground, gun ramps and moated keep can all be viewed.
The fort currently stores a treasure trove of objects from English Heritage's extensive reserve collections. Objects on display have been excavated from sites in the south east and south west. They include stonework, textiles, jewelry and furniture from many periods, as well as rarely-seen treasures on tour from stores in the north and east.