What is a roman fort?

What a roman fort is

The rampart was first built of turf, clay or earth with timber buildings inside, and from the early 2nd century many forts were rebuilt in stone; inside stood a headquarters building, the commander's house, granaries and barracks. Historic England notes that most forts in England date from the mid-1st to the mid-2nd century AD and that they are extremely rare south of a line from the Severn to the Trent. Wales was occupied by AD 78 and held by a network of auxiliary forts under the legions based at Caerleon and Chester; Gelligaer, for example, has two forts of the later 1st century AD. Some forts were occupied for only a few years, while others stayed in use for long periods. Fortlets, usually under 1 hectare, held small patrols, and legionary fortresses held a whole legion.

How roman forts look on LiDAR

Where a fort survives as earthworks, it shows as a rectangular platform with rounded corners, bounded by a rampart and one or more ditches, usually with gate gaps near the middle of the sides. A local relief model shows the rampart and the low remains of internal buildings and roads, and sky-view factor or negative openness picks out the outer ditches, which are often multiple. Many forts lie under later towns or have been ploughed, so only one or two sides may survive, sometimes as a scarp along a later field edge.

See LiDAR visualisations explained for what each method shows.

What can look like one

Medieval moated sites, later stock enclosures, landscape-garden earthworks and the rectangular enclosures of Iron Age and Romano-British farmsteads can look like forts. A Roman marching camp has the same rounded-corner plan but usually encloses a larger area behind a much slighter bank.

Protection

Many Roman forts are scheduled monuments, protected in England by the Ancient Monuments and Archaeological Areas Act 1979 and in Wales by the Historic Environment (Wales) Act 2023, and the forts of Hadrian's Wall are also part of the Frontiers of the Roman Empire World Heritage Site.

Examples on the LiDAR

Where they are

Counties with the most roman forts that have a page here.

More examples