Pevensey Castle

Pevensey Castle is a medieval castle and former Roman Saxon Shore fort at Pevensey in the English county of East Sussex. The site is a Scheduled Monument in the care of English Heritage and is open to visitors. Built around 290 AD and known to the Romans as Anderitum, the fort appears to have been the base for a fleet called the Classis Anderidaensis. The reasons for its construction are unclear; long thought to have been part of a Roman defensive system to guard the British and Gallic coasts against Saxon pirates, it has more recently been suggested that Anderitum and the other Saxon Shore forts were built by a usurper in an ultimately unsuccessful attempt to prevent Rome from reimposing its control over Britain.

• http://en.wikipedia.org/wiki/Pevensey Castle