Richborough Castle contains the ruins of a Roman Saxon Shore fort, collectively known as Richborough Fort or Richborough Roman Fort. It is situated in Richborough near Sandwich, Kent, in the United Kingdom.
Rutupiae or Portus Ritupis was founded by the Romans after their invasion of Britain in AD 43. Because of its position near the mouth of the Stour, Rutupiae was the major British port under the Romans and the starting point for their equivalent of Watling Street. Additional routes connected Durovernum with further ports at Dubris, Lemanis, and Regulbium. Earth fortifications were first dug on the site in the 1st century, probably as a storage depot and bridgehead for the Roman army. This transformed into a civilian and commercial town, which was later replaced by a Saxon Shore fort around the year 277. The later fort is believed to have been constructed by the rebel Carausius. The site is now under the care of English Heritage.
English Heritage website http://www.english-heritage.org.uk/visit/places/richborough-roman-fort-and-amphitheatre/
Address Richborough Road, Ash, Sandwich, Kent CT13, UK
Coordinates 51°17'23.657" N 1°19'36.922" E