In order to preserve Stonehenge, a United Nations World Heritage Site, for future archaeologists, the great stones needed a bit of a facelift. Laser scans helped figure out which areas of the ancient monument to repair. The stones date back about 4,500 years and are as high as 30 feet. These repairs will stop existing cracks from getting bigger, and replace previous repairs. And maybe someday we’ll figure out how Stonehenge got there.