What is a field system?

What a field system is

Prehistoric and Roman field systems are classed by layout: coaxial systems have one main axis, with most boundaries parallel to it or at right angles, while aggregate systems developed piecemeal and may be regular or irregular. Historic England's scheduling texts date regular aggregate field systems from the Bronze Age (about 2000 to 700 BC) to the end of the 5th century AD, and their small, roughly rectangular plots are often called 'Celtic' fields, a term with no cultural meaning. Medieval and later field systems include open fields of ridge and furrow, strip lynchets and the enclosed fields of later centuries. In the uplands, prehistoric fields are often marked by stone banks and clearance cairns.

How field systems look on LiDAR

Field systems show as networks of low banks, scarps and lynchets dividing the ground into plots, usually running across modern field boundaries. A local relief model shows the full layout best because the banks are low and extensive, and hillshade from several directions helps on slopes, where lynchets show as steps. Positive openness emphasises the lines of banks and walls, and sky-view factor shows ditched boundaries.

See LiDAR visualisations explained for what each method shows.

What can look like one

Removed modern and post-medieval field boundaries, natural geological banding, slope terraces and drainage patterns can look like ancient fields. Prehistoric systems usually ignore the present field pattern, while removed modern boundaries match the lines on old Ordnance Survey maps.

Protection

Some well-preserved prehistoric and Roman field systems 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.

Examples on the LiDAR

Where they are

Counties with the most field systems that have a page here.