Archaeologists had believed that the iconic stone monument was erected around 2500 BC, as described in the chronology below. One recent theory has suggested that the first stones were not erected until 2400-2200 BC, whilst another suggests that bluestones may have been erected at the site as early as 3000 BC (see phase 1 below).
The surrounding circular earth bank and ditch, which constitute the earliest phase of the monument, have been dated to about 3100 BC. The site and its surroundings were added to the UNESCO's list of World Heritage Sites in 1986 in a co-listing with Avebury Henge monument. It is a national legally protected Scheduled Ancient Monument. Stonehenge is owned by the Crown and managed by English Heritage, while the surrounding land is owned by the National Trust
Archaeological evidence found by the Stonehenge Riverside Project in 2008 indicates that Stonehenge served as a burial ground from its earliest beginnings. The dating of cremated remains found on the site indicate burials from as early as 3000 BC, when the initial ditch and bank were first dug. Burials continued at Stonehenge for at least another 500 years
Archaeologists have found four, or possibly five, large Mesolithic postholes (one may have been a natural tree throw), which date to around 8000 BC, beneath the nearby modern tourist car-park. These held pine posts around 0.75 metres (2 ft 6 in) in diameter which were erected and eventually rotted in situ. Three of the posts (and possibly four) were in an east-west alignment which may have had ritual significance; no parallels are known from Britain at the time but similar sites have been found in Scandinavia.
Salisbury Plain was then still wooded but four thousand years later, during the earlier Neolithic, people built a causewayed enclosure at Robin Hood's Ball and long barrow tombs in the surrounding landscape. In approximately 3500 BC, a large cursus monument was built 700 metres (2,300 ft) north of the site as the first farmers began to clear the trees and develop the area