"So this was a real Roman fort"

The occupying Roman forces in Britain built many military forts; some later also became civilian settlements or colonies for Roman settlers. The most important were at Isca (Caerleon), Deva (Chester), and Eboracum (York); another example can be found at Vindolanda near Hadrian's Wall.

See map of major forts and towns in Roman Britain here

 

For more information see Roman Forts in Britain by  Paul T. Bidwell

Try also Osprey's Roman Legionary Fortresses and Roman Auxiliary Forts