Basically, these stone markers were a like a primitive GPS—and the accuracy was quite astounding. Researcher Tom Brooks explains:

'The sides of some of the triangles are over 100 miles across on each side and yet the distances are accurate to within 100 metres. You cannot do that by chance.

'So advanced, sophisticated and accurate is the geometrical surveying now discovered, that we must review fundamentally the perception of our Stone Age forebears as primitive, or conclude that they received some form of external guidance.

Yes, "external guidance." Egyptians, Mayans, Stone Age Britons—it's got to be aliens. Either that, or Google has invented time travel conquer ancient landscapes starting with "Pangea Maps." [Daily Mail via Digg]

And really, why not? It may only be a concept, but if you have ever seen someone cut up meat with a hunk of obsidian or flint you know that ancient tools were wicked sharp. Plus, the fact that many survive today is a testament to durability. Although I think a handle might be in order here. I mean, I don't want to make it too easy to chop my finger off. [Matthias Kaeding via Dezeen via Boing Boing Gadgets]