In archaeology, a linear earthwork is a long bank of earth, sometimes with a ditch alongside.
Linear earthworks may have a ditch alongside which provides the source of earth for the bank and an extra obstacle.
Linear earthworks may function as defences, as boundary markers to define a territory, to mark out agricultural land, to control movement of people or animals, to levy customs duties or as a combination of some or all of these.
[1] A cross dyke is a type of linear earthwork believed to be a prehistoric land boundary.
In Ireland, the Black Pig's Dyke is an example of an Iron Age linear earthwork.