When I took a trip to England right after I graduated from college, one of the coolest places I visited was Stonehenge. There was a strong air of ancient mystery lurking among the massive stones arranged in a circle on the Salisbury plains. You couldn’t help but walk among the stones and think about where the enormous stones came from, who put them there, how in the world they got there — and what their mysterious purpose actually was.
Now scientists have answered the first question, at least in part: many of the smaller stones at the Stonehenge site came from ancient quarries in the Preseli Hills of Wales, and they were consciously mined and taken to Stonehenge, not deposited on the Salisbury plains by glaciers. Scientists used tools that allowed them to test the chemical composition of rocks in the quarry and match it to the composition of the rocks at Stonehenge. The tests are so precise that scientists were able to determine that the Stonehenge stones came from quarries in the northern part of the hills rather than the southern part — a finding that is significant, because it means that the stones were probably transported to the Salisbury plains over land, rather than floated there on rivers. The scientists also found mining tools at that date back to 3000 B.C., when the first stage of Stonehenge was built.
So now we know that, 5000 years ago, human beings mined large stones from Wales and then somehow dragged them 150 miles away, where they were arranged in circles that seem to be related in some way to the summer solstice. But we don’t know why ancient humans would undertake such an enormous task, or how they accomplished it. Unless someone invents a time machine, the answers to those questions probably will forever remain an unsolvable mystery — which is one reason why Stonehenge is so cool.