Earthwork in western England.
It stretches 169 mi (270 km) from the River Offa of Mercia to fortify the boundary between his kingdom and the lands of the Welsh; for centuries it marked the England-Wales boundary. It consisted of a plain bank (in places some 60 ft [18 m] high) and a ditch (12 ft [3.7 m] deep). Many sections remain, and a walking path now runs its length.