In May 1502, Portuguese explorer Miguel Corte-Real set out to find his brother Gaspar, who had disappeared somewhere near Newfoundland the previous year. Miguel also disappeared, and was assumed to have died in a storm …

… but no one has explained the inscriptions on Dighton Rock, a 40-ton boulder in the Taunton River in Massachusetts. It was customary for Portuguese explorers to inscribe their nation’s coat of arms as a land claim during the Age of Discovery, so some scholars believe that Miguel reached the New World and survived long enough to stake an early claim in Massachusetts. No other trace of him exists.