They're grand, historic fortresses, and to see the best of them you have to go to Europe -- or check out these photos.
Built high on a peak, Mont Saint Michel near Normandy, France, is one of medieval architecture's greatest achievements.
Through sieges, invasions, power struggles and murder, Edinburgh Castle in Scotland has stood the test of time.
Disney's landmark Sleeping Beauty castle is modeled after Neuschwanstein Castle, near Munich, Germany.
Glamis Castle has a reputation for being the most haunted castle in Scotland.
At 900 years old, Britain's Windsor Castle is the largest occupied castle and oldest royal residence in the world.
France's Chambord Castle was home to King Louis XIV and inspiration to painter Leonardo da Vinci and writer Moliere.
The 1,000-room Hampton Court Palace and Garden was once occupied by Henry the VIII.
Prague Castle provided a political and spiritual center for a country struggling toward unification.
At high tide St. Michael's Mount is cut off from the village of Marazion, roughly 600 miles south of London.
Despite its British location, Leeds Castle has many American connections.