A castle on an island is one thing, but a castle in a cave? Slovenia has just that in the form of Predjama Castle, built in the mouth of Postojna Cave, about 100 miles east of Venice, Italy. The in-cave location provided excellent defensive capabilities for the castle, whose history goes back at least to the 13th century; these days, cave tours are popular with visitors to the castle.
Just west of London, Windsor Castle is huge, and it’s hugely old, too. According to the British government, Windsor Castle — one of Queen Elizabeth II’s official residences — is the largest and oldest occupied castle in the world. Its history dates back to William the Conquerer; in the nearly 1,000 years since then, Windsor has expanded to a floor area encompassing about 480,000 square feet.
Prague Castle is widely considered the world’s largest castle complex. Dominating the Prague skyline from a hill overlooking the Vltava River, Prague Castle has an area of about 750,000 square feet. The castle was probably founded around 880, and it houses the crown jewels and relics of the Bohemian kings who ruled from there over the centuries.
Castles are usually associated with Europe and the Middle East, but you’ll also find them in places such as Japan. One of the loveliest Japanese castles is Himeji Castle, about 70 miles west of Kyoto, dating from the 14th century. Sometimes called the White Heron Castle for its white exterior, Himeji Castle is Japan’s largest and most visited castle. It’s also one of the best-preserved, being one of the few Japanese castles to survive virtually intact to the present day.
There’s one castle in continental North America that has housed sovereigns: Mexico’s Chapultepec Castle, which Emperor Maximilian I called home during the short-lived Second Mexican Empire in the 1860s. The castle’s hilltop location in present-day Mexico City was once sacred to the Aztecs (chapultepec is Náhuatl for "at the grasshopper’s hill"); the modern castle’s history dates to the 18th century.
Near the Skye road on the A87 near Dornie sits the bonnie Eilean Donan Castle at the mouth of Loch Duich. It was in ruinous state but between 1912 and 1932 it was rebuilt by Lieutenant Colonel John MaRae-Gilstrap. Eilean Donan Castle and its ghosts are now one of the top tourist attractions in Scotland.