Cord rig
Cord rig is the name given by archaeologists to a system of cultivation practiced in prehistoric and later upland Britain.
Spades were used to excavate raised banks for cultivation with channels running alongside for drainage. Where it survives, it consists of parallel ridges of earth around 1 m wide and 0.15 m high. The ridges are separated by shallow furrows in fields of around 0.5 hectares, or about 1-acre (4,000 m2). The presence of cord rig suggests nearby settlements and can be identified from aerial photography.[1]
In Northumberland, one example of cord rig has been identified running beneath, and therefore predating, Hadrian's Wall.