The Heel Stone is a single large block of sarsen stone standing within the Avenue outside the entrance of the Stonehenge earthwork, close to the main road (Highways Agency A344). In section it is sub-rectangular, with a minimum thickness of 2.4 metres, rising to a tapered top about 4.7 metres high. Excavation has shown that a further 1.2 metres is buried in the ground. It is 77.4 metres from the centre of Stonehenge circle. It leans towards the southwest nearly 27 degrees from the vertical. The stone has an overall girth of 7.6 metres and weighs about 35 tons. It is surrounded by the Heelstone Ditch.
Myths and legends of the Devil striking a "Friar's Heel" with a stone resulted in its eccentric name, Heel Stone. Some[who?] claim "Friar's Heel" is a corruption of "Freyja's He-ol" or "Freyja Sul", from the Nordic goddess Freyja and (allegedly) the Welsh words for "way" and "Sunday" respectively. It is doubtful whether any prehistoric standing stone has experienced as many name changes and interpretations. Only in the past three decades have scientists used the name Heel Stone consistently.
- Atkinson, R J C, Stonehenge (Penguin Books, 1956)
- Cleal, Walker, & Montague, Stonehenge in its Landscape (London, English Heritage 1995)
- Cunliffe, B, & Renfrew, C, Science and Stonehenge (The British Academy 92, Oxford University Press 1997)
- Hawley, Lt-Col W, Report on the Excavations at Stonehenge during the season of 1923 (The Antiquaries Journal 5, Oxford University Press, 1925)
- Newall, R S, Stonehenge, Wiltshire (Ancient monuments and historic buildings) (Her Majesty's Stationery Office, London, 1959)
- Pitts, M, Hengeworld (Arrow, London, 2001)
- Pitts, M W, On the Road to Stonehenge: Report on Investigations beside the A344 in 1968, 1979 and 1980 (Proceedings of the Prehistoric Society 48, 1982)
- Stone, J F S, Wessex Before the Celts (Frederick A Praeger Publishers, 1958)