Britain is full of ancient monuments: Medieval castles, Roman baths, Megalithic villages and giant hill figures. The landscape is littered with them - and the most famous of all is Stonehenge.
Stonehenge is Neolithic, which means it dates back to the late Stone Age (4,000-5,000 years ago), where polished stone weapons and implements were all the rage.
It's not the biggest henge in Britain, but Stonehenge is arguably the most picturesque and architecturally sophisticated. It's also the only surviving lintelled stone circle, which I don't need to tell you means it has horizontal blocks.
During the 5,000 years since its construction, the stones have either eroded, fallen over, sunk into the ground (Charles Darwin blamed this on earthworms - more on this shortly), or been removed by burly individuals seeking elaborate garden features. What you see at the site today are the scrappy remains.
Here's what it the original Stonehenge probably looked like:
Some natural questions to ask are:
- When was Stonehenge built?
- How was it built before the invention of the wheel?
- Who in their right mind built it?
- Why go to the effort of building Stonehenge anyway?
Stonehenge Was Built in Three Phases
Stonehenge was not built in one whack. Amazingly, it was expanded and updated by three different populations spanning 1,000 years.
That's not unlike modern-day architects slapping a shopping mall on the side of a medieval castle and no-one thinks to point out it's a desecration of history.
Regardless, the main conclusion you can draw from such a prolonged construction is that nobody at the start of the project was still alive to complain about delays at the end.
Phase I: 3000 BCE
Work at Stonehenge started around 3000 BCE. That makes it older than the Egyptian pyramids.
Initially, Neolithic people used picks made from deer antlers and mandibles to create a ditch, a bank and 50+ large holes. The resulting earthwork may have been a burial ground for the elite.
Analysis of human remains at the site suggests the bodies were interred over a period of 200 years.
Phase II: 2500 BCE
The nearest hardware store must have been busy, or closed, or not invented, because it was 500 years before thousands of workers returned.
They carried with them massive sarsen stones and smaller bluestones and dropped them into the existing holes. Now here's the ridiculous part about that sentence:
The sarsen stones weighed around 22,000kg each. That's about five male elephants, if you prefer your measurements in elephants.
I wouldn't know how to move a rock the size of one elephant, let alone five. Yet these people did, all the way from the Marlborough Downs, which is 32km away. What really takes the biscuit is that they did it all without the use of the wheel.
Engineers believe they rolled the stones over logs, which performed like conveyor belts. Still, such an operation would have required an obscene amount of blood, sweat and tears.
One recent theory suggests this undertaking marked a unification of Britain: a point where people from different regions across the land merged styles of building and pottery and other items.
It was a rather special time indeed.
Meanwhile, the smaller 3,500kg bluestones originated from the Preseli Hills in Wales some 225km away.
The idea that glaciers shifted the stones naturally has been largely dismissed. Most archaeologists think they were moved by human hands, first shipped via the sea and then rolled over land on logs.
With immense effort (namely thousands of people, extraordinary co-ordination, and lots and lots of griping) the stones were heaved into a horseshoe shape. They appear to be aligned to greet the sunrise and sunset on the mid-summer solstice.
That was certainly no accident. The landscape surrounding Stonehenge contains the remnants of numerous man-made ditches, wooden structures and even bigger henges significant to thousands of generations dating back to 10500 BC. In other words, this was long considered a terrifically sacred area.
Now here's a tasty nugget for the carpenter in you.
The builders of Stonehenge used joining techniques usually only seen in woodworking. Protruding tenons slotted into mortice holes to fit the upright stones and horizontal lintels together. Meanwhile, the lintels were connected to each other using tongue and groove joinery.
Phase III: 2000 BCE
The final build was completed another 500 years later, around 2000 BCE.
An unidentified megalomaniac decided to tinker around with the enormous rocks by having them vastly reorganised into the final arrangement you see today.
"Worth every death," he said.
Scientific Interest in Stonehenge
In more recent centuries, numerous well-known scientists have attempted to explain the purpose of Stonehenge.
In 1720, the astronomer Edmond Halley (of Halley's comet fame) engaged in man's first attempt to scientifically date Stonehenge.
Halley considered the position of the rising sun and calculated a build date of 460 BCE. Unfortunately, he was off by thousands of years - but credit to the rock-romancer for trying. Such an idea was revolutionary in his day.
In 1771 another astronomer, John Smith, pondered the 30 upright sarsen stones and noticed that 30 is the nearest integer you arrive at when dividing 365 days of the year by 12 months.
The inner circle may represent the lunar month, making the purpose of Stonehenge to be a terrifically elaborate calendar.
In the 1880s, Charles Darwin completed the first scientifically recorded excavations of the site. He discovered that the continual burrowing, digestion and excretion of soil by millions of earthworms had caused Stonehenge to sink into the ground.
Astonishingly, he calculated this to occur at a rate of five metres every 1,000 years. This implies Stonehenge has sunk by 22.5 metres since the giant stones were first laid down.
Today, breakthrough research is ongoing at the Stonehenge site.
Ground-penetrating radar, magnetometers, and other 3D mapping technologies are generating piles of new data on the nature of the stones and the burials. They have even discovered previously unknown henges in the surrounding underlying countryside.
In fact, like many areas of geological and environmental research, new technologies have produced so much data, they're yet to be fully analysed. Expect more revelations on the history of Stonehenge to come.
And yet, without a time machine, we may never fully comprehend who built Stonehenge and why.
"Those vast stones, standing in concentric rings in the middle of a basin on Salisbury Plain, carefully placed by who-knows-who thousands of years ago, must mean something. But nobody can tell us what. Not exactly. The clues that remain will always prove insufficient to our curiosity. Each archaeological advance yields more questions, and more theories to be tested. Our ignorance shrinks by fractions. What we know is always dwarfed by what we can never know." Ed Caeser, The Smithsonian