Fort, initially recommended by the Royal Commission Report of 1860, begun in 1879 and completed in 1889, the largest of the forts of the 'Chatham Ring', and the last fixed fortification built in England. With the development of high explosive shells during this period, the original design was heavily revised, and exposed structures such as caponiers were excluded due to their vulnerability. The fort was never provided with fixed armament. In 1902, only 7 machine guns were installed. The fort was officially abandoned as a defensive site in around 1906-7, although it remained garrisoned and was in use as an ammunition store and played some part in World War II as an anti-aircraft emplacement and observation post.
It was sold in 1963 and used as a tyre depot with tyres filling in the moat. Following a fire in 1976 the site became derelict but was brought back into use as office accommodation.
The fort is polygonal in plan surrounded by a deep ditch revetted in concrete. The ditch could be entirely swept by fire from counterscarp galleries in the three forward angles and by other positions flanking the entrance. The tunnels leading to the counterscarp galleries were providd with facilities for countermining in the event of a siege. The entrance was protected by a drawbridge. The entrance led to a long wide tunnel which divided the fort into two nearly equal parts, and whose cover acted as a traverse to give some protection against enfilade fire. There are traces of a World War I rectangular pillbox and anti-aircraft emplacements of World War II origin.
The site is a Scheduled Ancient Monument. For the other forts in the Chatham Ring, please see Fort Darland, 416048; the redoubt associated with Fort Twydall, 416066; Fort Luton, 416042, and Fort Bridgewoods, 416318.