Stonehenge is known as one of the most impressive prehistoric monuments in the world, famous for its massive stone circle, its precise alignment with the sun during the solstices, and the enduring mystery of how and why Neolithic people built it. Located on Salisbury Plain in southern England, it was constructed in stages over roughly 1,500 years, beginning around 3000 BCE. It holds UNESCO World Heritage status for its outstanding creative and technological achievements in prehistory.
A Monument Built in Three Stages
Stonehenge was not built all at once. Its construction unfolded across three major phases, each adding new elements to the landscape. The first stage, dated to roughly 3000 to 2935 BCE, involved digging a large circular enclosure more than 100 meters in diameter, defined by a ditch and earthen banks. This ring of earth, along with a series of pits known as the Aubrey Holes, formed the earliest version of the site.
The second stage, between about 2640 and 2480 BCE, saw further modifications to the interior. But it was the third stage, beginning around 2500 BCE, that produced the iconic stone structure people recognize today. During this period, enormous sarsen sandstone pillars were erected in an outer circle and capped with horizontal lintels, while smaller bluestones were arranged inside. A ceremonial avenue nearly 3 kilometers long was also dug from the monument to the River Avon between 2470 and 2280 BCE.
Two Types of Stone From Distant Sources
One of the most remarkable things about Stonehenge is where its stones came from. The monument uses two distinct types: large sarsen stones that form the outer ring and trilithons (pairs of uprights topped by a lintel), and smaller bluestones arranged closer to the center.
The bluestones, which include volcanic rocks like dolerites and rhyolites, were traced to the Preseli Hills in southwest Wales, over 200 kilometers from the site. How Neolithic people transported multi-ton stones that distance remains one of archaeology’s great puzzles. A 2020 geochemical study published in Science Advances determined that 50 of the 52 surviving sarsens share a consistent chemical signature, pointing to a common source at West Woods in Wiltshire, about 25 kilometers north of Stonehenge.
The stones themselves are enormous. Most of the outer sarsen uprights weigh over 26 tons each. The largest trilithon upright stands 7 meters high and weighs close to 45 tons. Even the lintels connecting the outer circle weigh about 7 tons apiece. The Heel Stone, an outlying marker, weighs roughly 35 tons.
Alignment With the Solstices
Stonehenge is perhaps best known for its relationship with the sun. The entire layout is oriented around the solstice axis. If you stand in the center of the stone circle on the summer solstice, the sun rises just to the left of the Heel Stone to the northeast. On the winter solstice, the sun originally set between the two uprights of the tallest trilithon and dropped down over the Altar Stone, a sandstone block placed directly across the solstice axis.
A laser survey of the monument confirmed that the stones framing this solstice line were the most carefully shaped of all, with precisely vertical sides designed to frame the sun’s movement. The Station Stones, placed at the corners of a rectangle around the edge of the surrounding ditch, further mark this alignment. The ceremonial avenue leading to the River Avon also follows it, aligned with the summer solstice sunrise in one direction and the winter solstice sunset in the other.
Archaeologists believe midwinter, not midsummer, may have been the more significant event for Stonehenge’s builders. When you walk up the avenue and enter the monument, the midwinter sunset alignment lies directly ahead of you, much like the way the most sacred part of a church faces the visitor upon entry.
A Major Prehistoric Burial Site
Stonehenge also served as a cemetery. Excavations in the 1920s recovered cremated remains of up to 58 individuals, making it one of the largest Late Neolithic burial sites known in Britain. A 2018 study in Scientific Reports used strontium isotope analysis on bone fragments from 25 of those individuals to determine where they had lived. At least 10 of the 25 did not grow up on the chalk geology around Stonehenge. Their isotopic signatures suggest they came from western Britain, most likely west Wales, the same region where the bluestones originated.
This finding points to something striking: Stonehenge was not purely a local project. People traveled long distances, possibly alongside the very stones being transported, and some were buried at the monument itself. The connection between the Welsh origins of the bluestones and the Welsh origins of some of the dead suggests deep, sustained ties between communities separated by hundreds of kilometers.
Competing Theories About Its Purpose
No written records exist from the people who built Stonehenge, so its exact purpose has been debated for centuries. The solstice alignments strongly suggest it functioned as a ceremonial site tied to seasonal cycles. The burials indicate it held deep significance as a place for honoring the dead.
Another prominent theory, advanced by archaeologists Timothy Darvill and Geoffrey Wainwright, proposes that Stonehenge was a place of healing. They point to the bluestones at the center of the circle, arguing that these particular rocks were valued for perceived medicinal or magical properties linked to healing springs near their source in Wales. Supporting this idea is an unusual concentration of skeletal trauma found in bones excavated from the area, suggesting that people suffering from injuries or illness may have traveled to the site seeking cures.
These theories are not mutually exclusive. Stonehenge likely served multiple overlapping purposes across its long period of use: a place to mark the turning of the year, to bury and remember the dead, and possibly to seek healing.
A Landscape Full of Hidden Structures
The stone circle is only the most visible part of a much larger ceremonial landscape. The Stonehenge Hidden Landscapes Project, using ground-penetrating radar and other geophysical tools, has revealed hundreds of previously unknown features beneath the surface. Among the most dramatic discoveries is a circle of more than 20 massive prehistoric shafts, each over 10 meters in diameter and 5 meters deep. These shafts form a ring more than 2 kilometers across, enclosing an area of over 3 square kilometers around Durrington Walls, one of Britain’s largest henge monuments located about 3 kilometers from Stonehenge.
The survey also uncovered new burial mounds, Bronze Age and Iron Age settlements, and prehistoric pits that appear to form their own astronomical alignments. Durrington Walls itself, with its own pit circle detected beneath its banks, appears to have been closely linked to Stonehenge. Together, these sites suggest that the entire surrounding landscape was shaped and reshaped over more than 2,000 years, from the early Neolithic well into the Bronze Age.
Visiting Stonehenge Today
Stonehenge is managed by English Heritage and draws enormous crowds. The year 2023 was the site’s best on record for family visits, with a 23 percent increase over the previous year. Visitors can walk around the stone circle on a paved path, and special access visits outside normal hours allow small groups to walk among the stones themselves. The solstices remain major events: thousands gather each June for the summer solstice sunrise, the one time of year when open access to the stones is free.
The monument’s UNESCO World Heritage designation, shared with the nearby Avebury stone circle and associated sites, recognizes it as an outstanding illustration of how prehistoric communities constructed monuments and continually reshaped their landscape over millennia. Among the specific qualities cited are the sheer size of its megaliths, the sophistication of its concentric plan, the unique use of both local sarsen sandstone and distant Welsh bluestone, and the precision of its construction.