Stonehenge, a megalithic monument in southern England, was built in stages from 2950 to 1600 BC. The first phase, Stonehenge 1, was a circular enclosure with wooden posts. Stonehenge 2 had a wooden structure and cremation burials. Stonehenge 3 used large stones arranged in various patterns, with the final phase creating the horseshoe and circular pattern visible today. The site’s purpose is disputed, but it was likely used for ceremonial and spiritual purposes and aligned astronomically. Construction may have required 242 years of labor, with stone working taking up to 2,300 years.
Located about two miles (3.22km) west of Amesbury in Wiltshire in southern England, Stonehenge is a megalithic monument, or large stone, composed of standing stones and earthworks. One of the most famous prehistoric sites in the world, Stonehenge was added to the United Nations Educational, Scientific and Cultural Organization (UNESCO) list of World Heritage Sites in 1986. While scientific dating of Stonehenge is complicated due to scant records of excavation and erosion, archaeologists generally agree that the complex was built in stages from 2950 to 1600 BC. In the 1940s, archaeologist Richard Atkinson proposed a three-stage construction. This theory has since been accepted and published by English Heritage, the UK’s consultant on England’s historic environment.
Stonehenge 1, the first phase of construction, took place from approximately 2950 to 2900 BC. During this phase, a circular enclosure approximately 360 feet (110 m) in diameter was constructed on Salisbury Plain. Within this enclosure is a second circle of 56 pits, generally believed to contain wooden posts.
Although evidence of Stonehenge 2 is no longer visible, archaeologists believe this second phase of construction occurred between 2900 and 2400 BC. Post holes in the center of the original circular enclosure suggest that a wooden structure was built at the inside the enclosure during this period. Furthermore, the outer ring of holes appears to have been used for cremation burials during the second phase of Stonehenge’s construction.
During the third phase of construction, which ran from about 2600 to 1600 BC, the builders appear to have abandoned the wooden materials in place of the large stones that can still be seen on the site today. Stonehenge 3 has been split into several sub-stages. During the first sub-phase, two concentric crescents of holes were dug in the center of the original enclosure. These holes have been fitted with 80 large blue stones.
The second sub-phase of Stonehenge 3 saw the arrival of large sarsen stones, brought to the site from a quarry on the Marlborough Downs. The following sub-phases denote periods of activity at the Stonehenge site during which the stones were rearranged into various patterns. During the final phase of construction, which occurred around 1600 BC, the bluestones were arranged in the horseshoe and circular pattern that is still visible today.
Much of the mystery surrounding the Stonehenge study has to do with the engineering feats required to build the monument. Archaeologists have suggested that the stones were transported using timber and rope. Wooden A-frames may also have been used to place the stones. It is estimated that the construction of the site may have required approximately 242 years of human labor, while the working of the stones may have required up to 2,300 years of labor.
While the significance of Stonehenge is much in dispute, most theories suggest that the site was built for ceremonial use. Archaeological evidence has indicated that the monument is aligned astronomically, giving particular importance to the solstice and equinox points. There has been some speculation that the monument could be used to predict solar and lunar eclipses. Additionally, many scientists believe that Stonehenge could have had spiritual significance and ritual uses for the prehistoric people who built it.