Devil's Ditch at Newmarket Racecourse

"It is not known who built the Dyke. It lies on the border of the Anglo-Saxon kingdoms of East Anglia and Mercia and given the ditch is on the west side, it was built by the East Anglians against their Mercian neighbours. The Anglo-Saxon Chronicle and other sources record the frequently tense relations between the two kingdoms, and it is likely that this provoked the need to strengthen the border and control access." See further information.