A Claudian Fort here was possibly destroyed during the Boudican revolt. A later Neronian period fort was abandoned shortly after its construction and the town grew up around it. The outline of the Neronian fort is in yellow, the town defenses are shown in brown.
http://roman-britain.co.uk/places/godmanchester.htm
http://www.godmanchester.co.uk/roman-duroviutum
http://www2.rgzm.de/transformation/unitedkingdom/smalltowns/smalltowns_englisch.htm
http://www2.rgzm.de/transformation/unitedkingdom/smalltowns/Img46.htm