Stonehenge: What We Actually Know About the World's Most Famous Prehistoric Monument
Stonehenge, on Salisbury Plain in Wiltshire, England, is the most studied prehistoric monument in the world. It has been excavated repeatedly since the seventeenth century, surveyed by every available geophysical and remote sensing technique, and subjected to specialist analysis ranging from astronomical alignment studies to ancient DNA sampling of its associated human remains. The results have transformed understanding of the monument over the past twenty years, replacing romantic speculation with a detailed, evidence-based picture that is more interesting and more complex than the popular narrative.
Construction History
Stonehenge was not built in a single phase. Its history spans approximately 1,600 years from the earliest earthwork to the final stone settings, and at least five major constructional phases are now identified.
Phase 1 (c. 3100 BCE): A circular ditch and bank, approximately 110 metres in diameter, was constructed. The Aubrey Holes — a ring of 56 pits just inside the bank — were dug at the same time. Cremated human remains were deposited in the Aubrey Holes over a period of at least 500 years; radiocarbon dating of these remains has been the primary means of establishing the monument's early chronology. This first Stonehenge was a cremation cemetery and circular earthwork, probably in use for communal burial and gathering.
Phase 2 (c. 2900–2600 BCE): The cremation deposits continued; the Aubrey Holes may have held timber posts at some point in this phase. The monument's use as a burial ground for perhaps 150–240 individuals (the remains represent more) spanned the entire third millennium BCE.
Phase 3 (c. 2500 BCE): The sarsen stones were erected. The sarsen circle (30 upright stones with a continuous lintel ring) and the central trilithon horseshoe (5 pairs of uprights with individual lintels) define the monument's present form. The sarsens were transported from Marlborough Downs, 25 km to the north, by a combination of land transport on wooden sledges and possibly water transport along a river route. The bluestones (approximately 60 igneous stones from the Preseli Hills in Wales, 240 km away) were also present in this phase, possibly rearranged from an earlier setting. The transportation of the bluestones from Wales is one of the most discussed logistics problems in British prehistoric archaeology; the most recent research favours overland transport via a glacially deposited intermediary cache.
The final phases (c. 2280–1600 BCE) involved rearrangement of the bluestones into their current double arc and horseshoe settings, and the construction of the Avenue — a pair of parallel earthen banks running from the monument to the River Avon.
Astronomical Alignments
The most consistently demonstrated astronomical feature of Stonehenge is the alignment of the principal axis to the midsummer sunrise and midwinter sunset. The Heel Stone, outside the monument to the north-east, marks the midsummer sunrise direction; the Great Trilithon faces south-west towards the midwinter sunset. These alignments are precise enough to be deliberate and are confirmed by the orientation of the Avenue along the same axis.
Mike Parker Pearson's Stonehenge Riverside Project (2003–2009) proposed that Stonehenge formed part of a paired ceremonial landscape: the stone monument was associated with death and the ancestor cult, while the nearby Durrington Walls — a massive circular earthwork enclosing timber post circles — was associated with life and the living community. The Avenue's alignment to the Avon connected the two monuments via a processional water route; the midwinter solstice was the primary ceremonial occasion connecting both.
Who Built It and Why
Ancient DNA analysis of human remains from Stonehenge and the wider Stonehenge-Avebury landscape, published by a team led by David Reich and Pontus Skoglund in 2019, demonstrated that the monument builders were largely migrants from the Anatolian farmer expansion that had reached Britain around 4000 BCE. These were the Early Neolithic people of the Windmill Hill culture, who built the Stonehenge enclosure and cremation cemetery in the third millennium BCE. The subsequent Beaker people — carrying Steppe-related ancestry — arrived around 2500 BCE and were largely responsible for the major stone-setting phases.
The function of the monument — as a gathering place for seasonal ceremony, an astronomical calendar, an ancestral shrine, or a healing sanctuary — remains debated. Recent analysis of the cremated remains from the Aubrey Holes found that many individuals were not local to the Stonehenge area: strontium and oxygen isotope values indicate origins in western Wales and elsewhere, suggesting that Stonehenge attracted pilgrims and burial from a considerable distance, even in its earliest phase.
The Wider Landscape
The Stonehenge Hidden Landscapes Project (2010–2014) used GPR, magnetometry, and other geophysical methods to survey 12 square kilometres around the monument. The results revealed at least 17 previously unknown monuments: a previously unknown row of burial mounds aligned on the Cursus (a long rectangular earthwork north of Stonehenge), a series of probable ritual pits along the Cursus boundary, and evidence for an installation of up to 90 upright stones or timber posts on the south side of Durrington Walls. These findings confirmed that Stonehenge was the focal point of one of the most densely monument-filled ceremonial landscapes in prehistoric Europe.
The Stonehenge Cursus, a 3 km-long rectangular earthwork to the north, predates the stone monument and was already ancient when the sarsens were raised; it is probably a ritual processional enclosure of the early fourth millennium BCE. The long barrow burials of the Neolithic period, visible as low earthen mounds across the plain, provided the ancestral focus around which the monument was built.
Visiting Stonehenge
Stonehenge is managed by English Heritage and is located on the A303 road approximately 2 km west of Amesbury. Entry is by timed ticket (booking in advance is essential); the visitor centre is some distance from the monument, connected by shuttle bus or footpath. The standard visit circuit takes visitors around the perimeter of the stone circle at a distance of approximately 10 metres; access to the stone circle itself is available for a limited number of people at dawn and dusk on special access visits, bookable separately. The visitor centre display on the construction, history, and people of Stonehenge is excellent.
The Avebury stone circle, 24 km to the north, and the Silbury Hill, West Kennet long barrow, and the Avebury World Heritage Site landscape offer a complementary experience in the same day.