Of all the world’s massive and mysterious monuments, the easiest to copy (save perhaps the pyramids) must be Stonhenge – provided you ignore the problem of how its multiple-ton blocks were lifted into place before modern machinery. Regardless, recent replicas abound. Inexplicably, the great Pi Stonehenge (also known as Stonehenge 3.141…) was left out of WebUrbanist’s listicle of 20 Creative Recreations of Stonehenge.