Stonehenge is a prehistoric World Heritage Site eight miles (13 kilometers) north of Salisbury in Wiltshire, England.[1] It is made of a henge,[2] with standing stones in circles.

There were three main building phases, each between about 3100 BC and 1950 BC. The first circle, ~3000 BC, was made of timber. The post holes for the timber have been found. Around 2600 BC, the builders gave up timber in favour of stone. Most of the construction took place between 2640 and 2480 BC.[3] Scientists have discovered that the Stonehenge builders originated from modern day Turkey from DNA analysis.[4][5]

The first stone circle was a set of 'bluestones'. The holes held up to 80 standing stones (shown blue on the plan), only 43 of which can be traced today.  The bluestones (made of dolerite, an igneous rock), are thought to have been brought from the Preseli Hills, 160 miles (260 kilometres) away in modern-day Pembrokeshire, Wales.[6]

This, the long distance human transport theory, was bolstered in 2011 by the discovery of a megalithic bluestone quarry at Craig Rhos-y-felin, near Crymych in Pembrokeshire. This is the most likely place where some of the stones were got.[6] Another theory is that they were brought much nearer to the site as glacial erratics by the Irish Sea Glacier.[7] This theory is not preferred, because there is no evidence of glacial deposition within southern central England.

Later, ~2400 BC, 30 huge grey sarsen stones were brought to the site. They were erected in a circle 33 metres in diameter, with lintels on top of the standing stones. The remaining bluestones were placed as an inner circle. The site was in use until the Bronze Age. The modern Stonehenge consists entirely of original stones, some of which have been replaced in upright position.

The stones may have come from a quarry about 25 miles (40 km) north of Stonehenge on the Marlborough Downs, or they may have been collected from a "litter" of sarsens on the chalk downs, which are closer.

The stones were 'dressed' (worked on) and given mortice and tenon joints. 30 were erected as a 33 metres (108 ft) diameter circle of standing stones, with a ring of 30 lintel stones resting on top. The lintels were fitted to one another using another woodworking method, the tongue and groove joint. Each standing stone was about 4.1 metres (13 ft) high, 2.1 metres (6 ft 11 in) wide and weighed about 25 tons.

There are also several passage tombs and many tumuli nearby.

Stonehenge, however, does have a number of satellite structures which are part of the 'ritual landscape':

No one knows who built Stonehenge or why they built it. During the summer solstice, the sunrise lines up with some of the stones in a particular way. This suggests that the arrangement of stones may work as a calendar. In Egypt and South America, similar ancient buildings can be found. They also show the time of the solstice.

Stonehenge itself is owned by the Crown and managed by English Heritage. The surrounding land is owned by the National Trust.[8][9]

The World Heritage Site includes Avebury and Stonhenge together, though they are quite distinct.

Media related to Stonehenge at Wikimedia Commons
Coordinates: 51°10′43.8″N 1°49′34.3″W﻿ / ﻿51.178833°N 1.826194°W﻿ / 51.178833; -1.826194