The intriguing history of Stonehenge

Stonehenge was built in several phases over more than 1,500 years, starting around 3100 BC in the Neolithic period.

The very earliest structure probably consisted of a circular ditch and bank, known as a 'henge'.

During the earliest phase of Stonehenge, there was the creation of the 'Aubrey Holes': 56 pits that were dug inside the ditch.

As a result, researchers believed that this site, and the pits, was used for ceremonial purposes.

Additional excavations have revealed that Stonehenge was also used as a burial site during its earliest phase, with human remains dating from around 3000 BC found in the circular ditch.

One of the most mysterious elements of the site is an ancient processional pathway that connects Stonehenge with the River Avon, known as the 'Avenue'.

It is nearly 3 kilometers long and was constructed during the Stonehenge 3 period, between 2600 and 1700 BCE.

It is aligned with the sunrise of the summer solstice, which suggests its use for ceremonial or ritual purposes.

The Avenue consists of a pair of parallel banks about 34 meters apart with outer ditches.

It starts near the River Avon and runs north-northwest for about 1 kilometer before turning west and eventually leading to the northeastern entrance of Stonehenge.

The first smaller stones were brought to the site around 2600 to 2500 BC.

Known as bluestones, they were transported over a distance of 150 miles from the Preseli Hills in Wales and were arranged in a double circle within the existing earthwork enclosure.

The bluestones may have been transported to Stonehenge via the Avenue using a combination of log rollers and rivers.

However, it is not entirely clear why these stones were brought to the site. They may have had a spiritual or symbolic significance.

There is some evidence that they could have been used for their acoustic properties and possibly for ritual purposes.

Over time, Stonehenge underwent a series of different transformations. The original bluestone circle was rearranged at one point. 

Then a larger circle of sarsen stones was added. These sarsen stones, which are up to 30 feet tall and weigh up to 25 tons, were transported from the West Woods near Marlborough Downs, about 15 miles (25km) north of the site.

They form the iconic outer circle and trilithons, which were erected later, between 2500 and 2400 BC.

They famously use mortise and tenon joints to hold the lintels on top of the uprights.

One of the most prominent sarsen stones is known as the Heel Stone, which is located outside the entrance of the Stonehenge earthwork.

It is a single, massive block standing within the Avenue, approximately 77.4 meters from the center of the Stonehenge circle.

The stone is 2.4 meters thick with a height of about 4.7 meters above ground, while an additional 1.2 meters is still buried below the surface

Starting around 2500 BC, a new group of people arrived in the area, known as the Beaker People.

This group brought with them a distinctive bell-shaped pottery, which had spread across Europe and reached Britain through large-scale migration. 

Genetic studies have shown that the arrival of the Beaker people led to a near-complete replacement of the existing Neolithic population in Britain, resulting in a 90% change in the genetic makeup of the population.

This migration also coincided with the introduction of new technologies and practices, including metalworking, which marked the transition from the Neolithic to the Early Bronze Age.

The new Beaker People added a series of earthen mounds to the site.

These are thought to have been used as burial sites for important members of their community.

After 1500 BC, Stonehenge saw little alteration, and the monument's active construction phases largely ceased around this time.

The last known construction activities involved the digging of the Y and Z Holes around 1600 BC.

These holes were likely intended for additional stones, but they were never filled. 

One of the most fascinating aspects of Stonehenge is its alignment with the summer and winter solstices, particularly the sunrise on the summer solstice, when the sun aligns perfectly with the Heel Stone.

Observers standing within the stone circle can see the sun rise over the Heel Stone during the solstice.

However, much of what we think we know about Stonehenge relies entirely on archaeological findings, because there was no written history about the site.

As a result, there is a lot we can never know. Over the years, people have imagined many different legends to help explain the monument.

For example, in the 12th century, the writer Geoffrey of Monmouth claimed that the monument was built by Merlin, the wizard of Arthurian legend.

Other legends suggest that the stones were brought to the site by giants or that they were transported by aliens.

In more recent times, Stonehenge has been associated with Druidic practices, and it has become a site for modern-day pagans to gather and celebrate the solstices and equinoxes.

A more credible theory was put forth by archaeologists Geoffrey Wainwright and Timothy Darvill in 2008.

They proposed that Stonehenge may have functioned as a healing center, based on the discovery of human remains showing signs of injury and illness.

Regardless of its historical purpose, today Stonehenge attracts over 1.5 million visitors annually, making it one of the most popular tourist destinations in the UK.

People come for a variety of reasons, including all of those mentioned above.

In the modern era, people wanted to find out as much concrete evidence about the site as they could.

John Aubrey, a 17th-century antiquarian, was one of the first to study Stonehenge in detail and is credited with discovering the circle of pits now known as the Aubrey Holes.

Then, in the early 18th century, the site was surveyed by the antiquarian William Stukeley, who made a detailed map of the site and proposed that Stonehenge was a temple of the Druids.

In the early 20th century, parts of Stonehenge were restored, with several stones re-erected to prevent them from falling and to maintain the structure for future generations.

It wasn't until 1986 that Stonehenge was finally designated as a UNESCO World Heritage Site in recognition of its cultural and historical significance to Britain.

In 2015, a team of archaeologists using high-tech sensors as part of a collaboration between the University of Birmingham and the Vienna-based Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology discovered evidence of a large stone circle, known as a 'superhenge', or Durrington Walls, located about 2 miles from Stonehenge.

It is one of the largest known henge monuments in Britain, with a diameter of about 500 meters. 

Durrington Walls was made up of 90 standing stones, some originally measuring 4.5 meters tall, which had been buried under a bank of earth for millennia.

This was thought to have been a settlement or gathering place, possibly for those who built or used Stonehenge.

Excavations have revealed evidence of houses and feasting, suggesting it was a lively community space.

The proximity and alignment with Durrington Walls led archaeologist Mike Parker Pearson to suggest that Stonehenge was part of a larger landscape associated with rituals of life and death, connecting the living at Durrington Walls with the ancestors at Stonehenge.