Castles. The word conjures images of kings, queens and Knights of the Round Table. These enduring stone structures are often shrouded in legends and myths as elusive as the mists that rise from their moats. During the Middle Ages, castles served as fortresses; during the Renaissance and Reformation, they housed royals and painters, artisans and playwrights. Today, castles serve as testimony to centuries past, offering visitors a glimpse into what life must have been like for the lords and ladies of the manor. Here, we present our choices of the best castles the world has to offer.