The monument includes a stretch of the World War II defence or ‘stop line’ known as The Eastern Command Line which was constructed in 1940 as part of a series of lines of defence to counter the threat of a cross-channel invasion by German forces from occupied France. The Eastern Command Line was the longest and most heavily fortified position in East Anglia and ran from Wivenhoe on the Essex coast to The Wash west of Kings Lynn. Part of the defensive line runs to the north of the town of Colchester before following the River Colne westwards to Chappel Viaduct at which point it turns to run north along the railway leading to Bures. The viaduct represents a gap in the natural barrier afforded by the river and the man-made protection of the railway embankment. Consequently it was heavily fortified with pillboxes, gun emplacements and anti-tank barriers. The defences include examples of the four major types of pillbox built along the Eastern Command Line (nodal point, artillery, infantry and anti-aircraft) in addition to lines of anti-tank cubes and two spigot mortar emplacements. For full description, see scheduling notes. <1>