[17] Another Mesolithic astronomical site in Britain is Warren Field in Aberdeenshire, which is considered the world's oldest lunisolar calendar, corrected yearly by observing the midwinter solstice.

[20][21] Salisbury Plain was then still wooded, but, 4,000 years later, during the earlier Neolithic, people built a causewayed enclosure at Robin Hood's Ball, and long barrow tombs in the surrounding landscape.

"[20] The first monument consisted of a circular bank and ditch enclosure made of Late Cretaceous (Santonian Age) Seaford chalk, measuring about 360 feet (110 m) in diameter, with a large entrance to the north east and a smaller one to the south.

[6][7] A 2018 study of the strontium content of the bones found that many of the individuals buried there around the time of construction had probably come from near the source of the bluestone in Wales and had not extensively lived in the area of Stonehenge before death.

It is generally accepted that the bluestones (some of which are made of dolerite, an igneous rock), were transported by the builders from the Preseli Hills, 150 miles (240 km) away in modern-day Pembrokeshire in Wales.

[35] 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, which is the most likely place for some of the stones to have been obtained.

Although this would seem the most impressive phase of work, Stonehenge 3 IV was rather shabbily built compared to its immediate predecessors, as the newly re-installed bluestones were not well-founded and began to fall over.

Geoffrey Wainwright, president of the Society of Antiquaries of London, and Timothy Darvill, of Bournemouth University, have suggested that Stonehenge was a place of healing—the primeval equivalent of Lourdes.

[57] On the other hand, Mike Parker Pearson of Sheffield University has suggested that Stonehenge was part of a ritual landscape and was joined to Durrington Walls by their corresponding avenues and the River Avon.

[44] Both explanations were first mooted in the twelfth century by Geoffrey of Monmouth, who extolled the curative properties of the stones and was also the first to advance the idea that Stonehenge was constructed as a funerary monument.

According to a team of British researchers led by Mike Parker Pearson of the University of Sheffield, Stonehenge may have been built as a symbol of "peace and unity", indicated in part by the fact that at the time of its construction, Britain's Neolithic people were experiencing a period of cultural unification.

[47][58] Stonehenge megaliths include smaller bluestones and larger sarsens (a term for silicified sandstone boulders found in the chalk downs of southern England).

[38] Researchers from the Royal College of Art in London have discovered that the monument's igneous bluestones possess "unusual acoustic properties" – when struck they respond with a "loud clanging noise".

[59] There is evidence to suggest that despite the introduction of farming in the British Isles, the practice of cereal cultivation fell out of favor between 3300 and 1500 BC, with much of the population reverting to a pastoralist subsistence pattern focused on hazelnut gathering and pig and cattle rearing.

In 1877, Charles Darwin dabbled in archaeology at the stones, experimenting with the rate at which remains sink into the earth, for his book The Formation of Vegetable Mould Through the Action of Worms.

In April 2008, Tim Darvill of the University of Bournemouth and Geoff Wainwright of the Society of Antiquaries began another dig inside the stone circle to retrieve datable fragments of the original bluestone pillars.

[93][94] In 2014, the University of Birmingham announced findings including evidence of adjacent stone and wooden structures and burial mounds near Durrington, overlooked previously, that may date as far back as 4000 BC.

In July 2020, a study led by David Nash of the University of Brighton concluded that the large sarsen stones were "a direct chemical match" to those found at West Woods near Marlborough, Wiltshire, some 15 miles (25 km) north of Stonehenge.

[100][g] In February 2021, archaeologists announced the discovery of "vast troves of Neolithic and Bronze Age artifacts"[101] while conducting excavations for the proposed highway tunnel near Stonehenge.

[116] Another legend tells how the invading Saxon king Hengist invited British Celtic warriors to a feast but treacherously ordered his men to massacre the guests, killing 420 of them.

[118] The plot bought by Chubb and gifted to the nation was only 30 acres (12 ha) in size, and various buildings stood within clear sight of the monument, the most prominent being Stonehenge Aerodrome.

[135] The earlier rituals were complemented by the Stonehenge Free Festival, loosely organised by the Polytantric Circle, held between 1972 and 1984, during which time the number of midsummer visitors had risen to around 30,000.

This "exclusion-zone" policy continued for almost fifteen years: until just before the arrival of the twenty-first century, visitors were not allowed to go into the stones at times of religious significance, the winter and summer solstices, and the vernal and autumnal equinoxes.

In the survey of conditions at 94 leading World Heritage Sites, 400 conservation and tourism experts ranked Stonehenge 75th in the list of destinations, declaring it to be "in moderate trouble".

[175] In 2009, the government gave approval for a £25 million scheme to create a smaller visitors' centre and close the A344, although this was dependent on funding and local authority planning consent.

The plan had received opposition from a group of "archaeologists, environmentalists and modern-day druids" according to National Geographic but was supported by others who wanted to "restore the landscape to its original setting and improve the experience for visitors".

[190] Later, repeated vandalism in the 1980s and 1990s led the authorities to deploy up to hundreds of police, erect barriers around Stonehenge, and impose exclusion zones up to six kilometres from the archaeological monument.

Leader of the Labour Party Sir Keir Starmer called the vandalism "outrageous" while deeming Just Stop Oil as "pathetic", demanding that the activists and anyone else involved with the act "face the full force of the law".

[202] The archaeologist Mike Pitts said the impact of the protest was "potentially quite concerning", and said that the megaliths were fenced off and guarded to protect their surfaces, which were entirely covered in prehistoric markings that have not been fully analysed.

[206] Conversely, Sarah Kerr, a lecturer in archaeology at University College Cork, noted that the effects of climate change pose a much greater threat to Stonehenge and other British heritage sites than Just Stop Oil's protest, which was washed away without causing damage.