Roman Fort - World History Encyclopedia

The Roman army constructed both temporary and permanent forts and fortified military camps (castrum) across the frontiers of the empire

A Visitor's Guide to Rome's Frontier in Germany - World History

Roman Britain, History & Map

Roman Warfare - World History Encyclopedia

Roman Army - World History Encyclopedia

The Encyclopedia of the Roman Army

The Kingfisher History by Kingfisher Publications

Ancient Roman architecture - Wikipedia

Vindolanda Roman Fort (Illustration) - World History Encyclopedia

Castra - Wikipedia