Stonehenge, the mysterious site at the center of the universe

Over a thousand years to build a unique archaeological work

Walking through the halls of London’s British Museum in search of the secrets of Stonehenge, one of the world’s oldest and most mysterious monuments, means immersing oneself in a historical period of enormous transformation. Our very concepts of human life and coexistence were reshaped.

Coming to a close just a few days ago, the exhibition “The World of Stonehenge” brought the history of Britain—and all of Europe, between 4,000 and 1,000 BC —to London’s famous museum. This vast period is often referred to as the “Stonehenge Age.”

Behind every stone and every object is the history of human evolution, which links the Italian Alps to the English prairies. Through their incredible mystical and cultural heritage, they’ve become both a place of worship and a tourist attraction.

Not surprisingly, around mid-June, more than 6,000 people gathered at the foot of the great stones of Stonehenge to celebrate the summer solstice.

History of Stonehenge: the world's oldest system of megalithic architecture

A calendar, a Celtic shrine, a cemetery or even an astronomical observatory: Stonehenge could be any of these things, or all of them combined. Therein lies the mystery of this incredible archaeological site, often seen as one of the world’s most beguiling. It’s difficult to interpret the significance of this man-made structure; historians date its construction to around 3000 BC.

But that was just the start of construction work that lasted for an estimated fifteen centuries, starting with the first moat built in the site’s southern end. Half a millennium after the first moat, the first circle was built, concentric to the moat and made of wood. Around 2,000 BC, the wooden circle was replaced by a new circle of sandstone stones, the so-called trilithons.
The work was not completed until 1550 BC, when the Bluestone stones were brought from Wales. Altogether this led to the completion of the oldest system of megalithic architecture that soon became the world’s best-known cromlech (“stone circle” in the Breton language), consisting of a circular set of squared blocks topped by horizontal lintels. The Stonehenge circle is then surrounded by a moat that is about 100 metres (330 feet) in diameter and 6 metres (20 feet) wide, made, according to historians, to demarcate a sacred area linked to sun worship.

Even today, sun worship is what attracts most visitors to this well-trodden tourist site. The most recent record set was in 2005 when, at dawn on June 20 on another summer solstice, 19,000 people celebrated sunrise straight from Stonehenge. On this special day, as well as on December 21 (the winter solstice), the Sun rises at the top of the trilithon, the huge stone arch at the center of the site.

Covid-19 forced Stonehenge to be closed to the public, along with all other museums in the United Kingdom. Today, however, Stonehenge is open again and thousands of people have returned to its green lawns to take in this incredible work of humanity.

Mysteries of prehistoric engineering

Understanding the secrets of Stonehenge is like trying to understand the most complex engineering techniques—an exercise not many people are well-equipped to do!

Even today, thousands of years after its construction, no one can explain exactly how this prehistoric monument was built. The trilithons, or these gates made up of two mullions and a lintel, are made from heavy sandstone blocks that weigh about 20 tons each and measure 9 metres (30 feet) high, two of them driven into the earth.

It is a similar mystery for the so-called Bluestones, which make up the outermost circle of the site and are found only in South Wales, about 200 kilometres (124 miles) away from the site. Despite being smaller—the average weight of each is about 4 tons—their transport across Brittany was likely one of the most complex challenges for the people of that time.

The last of the mysteries, however, concerns the placement of the stones themselves. Their perfect alignment with the summer and winter solstices opens up important questions about the knowledge of these peoples, who, centuries before the spread of mathematics and astronomy, had been able to read the movements of the stars and calculate with absolute precision where to place their monument.

Salisbury Plain: new life for a perennial monument

It took years and years of study, but eventually, scientists’ and historians’ research yielded some significant answers to the many mysteries of Stonehenge. The monument never may have come to fruition without the tenacity of those who worked on it, who were able to continue the work across generations.

The project was passed down for more than a thousand years. Today the fruits of their labor are well-preserved and remain one of the most important monuments in the United Kingdom. Stonehenge has transformed Salisbury Plain (13 kilometres or 8 miles from the town of the same name) in Wiltshire into a place of pilgrimage and transit for hundreds of thousands of people.

To protect the site and to ease traffic congestion in the area, the UK’s National Highways has developed a scheme to upgrade the A303 into dual carriageway, partly in a tunnel, between Amesbury and Berwick Down, passing near Stonehenge.

The MORE joint venture—comprising the Webuild Group, FCC Construccion and BeMo Tunneling—has been selected as the preferred bidder for this project to construct a 13-kilometre-long (8-mile-long) dual carriageway with a tunnel approximately 3.3 kilometres (2 miles) long, passing beneath the World Heritage Site landscape and further away from the Stonehenge monument.