Archaeologists have discovered a major new prehistoric monument only a short distance away from Stonehenge. Fieldwork and analysis have revealed evidence for 20 or more massive, prehistoric shafts, measuring more than 10 metres in diameter and 5 metres deep. These shafts form a circle more than 2 kilometres in diameter and enclose an area greater than 3 square kilometres around the Durrington Walls henge, one of Britain’s largest henge monuments, and the famous, smaller prehistoric circle at Woodhenge.