http://www.wired.com/science/discoveries/magazine/17-05/ff_guidestones "The strangest monument in America looms over a barren knoll in northeastern Georgia. Five massive slabs of polished granite rise out of the earth in a star pattern. The rocks are each 16 feet tall, with four of them weighing more than 20 tons apiece. Together they support a 25,000-pound capstone. Approaching the edifice, it's hard not to think immediately of England's Stonehenge or possibly the ominous monolith from 2001: A Space Odyssey. Built in 1980, these pale gray rocks are quietly awaiting the end of the world as we know it."