Dighton Rock

One of the most curious objects on American soil has been captivating the curious since the 17th century. Dighton Rock, originally found in the Taunton River, is a 40-ton boulder that is ringed with a series of carved petroglyphs that can be mapped to no known Earthly language. Scientists have attributed the carvings to a wide array of creators-some think Viking explorers carved them, some believe they're Phoenician in origin, and a recent book even alleged they were left by a Chinese expedition. We're no closer today to figuring out their actual origin.