Stonehenge, near Amesbury, England, boasts one of the globe’s most famous ancient standing stones, dating back to 2,500 B.C. Even older stone circles can be found in Japan and Australia. In the United States, two ancient stone arrangements lie at the bottom of the Great Lakes. One is a 9,000-year-old caribou hunting structure on an ancient land bridge that once connected northeast Michigan to southern Ontario, now submerged under Lake Huron. The other is a yet-to-be-studied arrangement of stones at the bottom of Lake Michigan, discovered in 2007. Despite its potential significance, a lack of funding has prevented archaeologists from fully excavating the site. Notably, Lake Michigan was dry until 15,000 years ago.