Castel del Monte

On a bare hill in Apulia, southern Italy, about an hour inland from Bari, Castel del Monte stands as a perfect octagon against the sky. Frederick II raised it around 1240, and he was no ordinary emperor. Called Stupor Mundi, the Wonder of the World, he spoke six languages, kept Muslim guards, and was excommunicated twice by the Pope. His castle follows the same strange logic. Eight towers, eight rooms on each floor, yet no moat, no drawbridge, no well, and no real defenses. No one has settled what it was really for. After Frederick died in 1250, it became a prison, then was abandoned to shepherds, then restored.