The stones of Stonehenge have endured centuries of weathering and erosion.
Credit: ivanovsky | Shutterstock
Stonehenge is an enigmatic prehistoric monument located on a chalky plain north of the modern-day city of Salisbury, England. It was started 5,000 years ago and modified by ancient Britons over a period of 1,000 years. Its purpose continues to be a mystery.
The biggest of its stones, known as sarsens, are up to 30 feet (9 meters) tall and weigh 25 tons (22.6 metric tons) on average. It is widely believed that they were brought from Marlborough Downs, a distance of 20 miles (32 kilometers) to the north. Smaller stones, referred to as “bluestones” (they have a bluish tinge when wet or freshly broken), weigh up to 4 tons and most of them appear to have come from the Preseli Hills in western Wales, a distance of 156 miles (250 km). It’s unknown how people in antiquity moved them that far; water transport was probably used for part of the journey. Scientists have raised the possibility that during the last ice age glaciers carried these bluestones closer to the Stonehenge area and the monument’s makers didn’t have to move them all the way from Wales.
Although construction of Stonehenge began about 5,000 years ago, the area appears to have been of symbolic importance for a much longer period of time.
As early as 10,500 years ago three large pine posts, which were totem poles of sorts, were erected at the site. Then around 5,500 years ago two earthworks known as Cursus monuments were erected, the longest of which ran for 1.8 miles (3 km). The purpose of these structures is unknown.
Construction of the monument
The building of Stonehenge started about 5,000 years ago with the creation of an earthwork enclosure. The presence of post holes suggests that either bluestones or upright timber posts were propped up on the site. In addition, archaeologists have found numerous cremation burials dating to this time and the centuries that followed. Recent research suggests that up to 240 people were buried in total, making Stonehenge the large Neolithic burial site in Britain.
Around 4,600 years ago construction ramped up with the erection of dozens of bluestones in a double circle at the site. This monument was not to last and by 4,400 years ago it had been replaced by something far grander.
The new structure had a series of sarsen stones erected in the shape of a horseshoe, with every pair of these huge stones having a stone lintel connecting them. In turn, a ring of sarsens surrounded this horseshoe, their tops connecting to each other, giving the appearance of a giant interconnected stone circle surrounding the horseshoe.
By 4,300 years ago this monument had been expanded to include the addition of two bluestone rings, one inside the horseshoe and another between the horseshoe and the outer layer of interconnected sarsen stones.
This would be the end of major construction at Stonehenge. As time went on the monument fell into neglect and disuse, some of its stones fell over while other were taken away. [In Photos: A Walk Through Stonehenge]
Significance to its makers
There are numerous theories as to why Stonehenge was built. At the time it was made, people in the area were herders and farmers. They left no written records behind.
An “avenue” connecting Stonehenge with the River Aven is aligned with the solstice. In addition, research at the nearby ancient settlement of Durrington Walls, a site that also contains a series of wooden pillars, shows that pigs at the site were slaughtered in December and January, suggesting that the winter solstice was marked at Stonehenge.
The burials at Stonehenge offer another clue. Recent research indicates that the burials took place from its beginning, around 5,000 years ago, to its high point when the sarsen stones were set down. Among the burial goods is a mace head, an item historically associated with elite members of society. This discovery raises the question whether the people buried at the monument were local leaders and Stonehenge, in some way, commemorated them.
In 2014, scientists unveiled the results of a four-year survey of the landscape around Stonehenge. Using non-invasive techniques like ground-penetrating radar, the researchers detected signs of at least 17 previously unknown satellite shrines. People may have traveled considerable distances to come to Stonehenge, project leader Vincent Gaffney, an archaeologist at the University of Birmingham in the U.K., told Live Science. "It's part of a much more complex landscape with processional and ritual activities that go around it."
A monument of unification
One new theory about Stonehenge, released in 2012 by members of the Stonehenge Riverside Project, is that Stonehenge marks the “unification of Britain,” a point when people across the island worked together and used a similar style of houses, pottery and other items.
It would explain why they were able to bring bluestones all the way from west Wales and how the labor and resources for the construction were marshaled.
In a news release, professor Mike Parker Pearson of the University of Sheffield said that "this was very different to the regionalism of previous centuries. Stonehenge itself was a massive undertaking, requiring the labour of thousands to move stones from as far away as west Wales, shaping them and erecting them. Just the work itself, requiring everyone literally to pull together, would have been an act of unification."