Built to protect and entertain royalty, ancient castles naturally possess a lasting beauty. Anyone who has done even a little bit of traveling knows the drill – if the place you are visiting has a castle, taking an overpriced tour that ends with you being ripped off in an overpriced gift shop is a non-negotiable. The castles of the world are some of the most popular historic sites on the planet. The list of world castles is as varied as it is long and contains everything from world famous castles to hidden castles and ruined castles which are now but a shadow of their former glory. But unlike the gated compounds of yesteryear, modern travelers can now step inside their historic gates.