Cross dyke

A cross dyke or cross-dyke (also referred to as a cross-ridge dyke, covered way, linear ditch, linear earthwork or spur dyke) is a linear earthwork believed to be a prehistoric land boundary that usually measures between 0.2 and 1 kilometre (0.12 and 0.62 mi) in length. A typical cross dyke consists of one or more ditches running in parallel with one or more raised banks. Univallate cross dykes typically have a flat-bottomed ditch while the ditches of multivallate cross dykes possess a V-shaped cross-section. A defining characteristic of a cross dyke is that it cuts across the width of an upland ridge or the neck of an upland spur. Cross dykes generally occur at altitudes over 150 metres (490 ft) above mean sea level.