The Engineering of Stonehenge
Learn about the engineering and architecture of Stonehenge, Britain’s most famous prehistoric monument.
Article By: Francesca Burke
Last Update: September 2019
Stonehenge, a ring of standing stones in Wiltshire, England, is one of Britain’s most famous prehistoric monuments. It’s also a World Heritage Site. Located about 90 miles from London and 2 miles from the town of Amesbury, today Stonehenge is revered as an icon of the British countryside. Stonehenge is also famous as a spectacular feat of engineering: it is the only surviving lintelled stone circle in the world.
Origins of Stonehenge
It’s believed that Stonehenge was first used as a cremation ceremony site. It was built around 3,000 BCE as an earthen circular enclosure reinforced with 56 stone or timber blocks. Interestingly, the ditch was dug using antler tools! It’s believed the area was used for cremations for several hundred years.
Constructing the Stone Circle
During the late Neolithic period, around 2500 BCE, the famous stones were added after a great deal of organised effort. Stonehenge consists of large sandstone blocks called sarsens and smaller ‘bluestones’ (so-called because they have a bluish tinge when freshly broken or wet).
Initially, the sarsens formed an inner horseshoe and an outer circle, while the bluestones were set up between them in a double arc. 200 or 300 years later the bluestones were rearranged to form a circle and inner oval (which was again later altered to form a horseshoe).
A bird’s eye view of the interlocking sarsens, from Historic England
Stonehenge’s main stones were raised upright by first digging a hole with a sloping side. The back of the hole was lined with wooden stakes, then the stone moved into position and hauled upright using plant-fibre ropes and most likely a wooden A-frame (weights may have helped tip the stone upright). Then the hole was packed with rubble. The horizontal stones were probably raised using timber frames, with the vertical and horizontal stones slotted together using mortice holes and tenons.
To get a better idea of the stages of constructing Stonehenge, download English Heritage’s plan showing each phase of construction.
Illustration by Peter Dunn © Historic England
Adding to the mystery of Stonehenge is that its purpose has been disputed. Theories have included it as a coronation place for Danish kings, an astronomical computer, a Druid temple and a Roman temple. We know it was the site of some great parties, but not a lot else!
Today it’s generally agreed that Stonehenge was aligned with the movements of the sun. The main axis of the stones is aligned upon the solstitial axis, and at midsummer, the sun rises close to the ‘Heel Stone’, a large sarsen stone outside the entrance to the Stonehenge earthwork. At midwinter, the sun sets in the gap between the two tallest trilithons. The seasonal cycles were clearly important to the builders of Stonehenge, but we may never know exactly what its intended purpose was.
North East of Stonehenge, from Historic England