This modern French ossuary contains the jumbled bones of 130,000 WWI soldiers.

Site of one of World War I's most horrific scenes.

The Sun King's military models, saved from the Louvre.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

This medieval castle overlooking the Elzbach river looks just like it did hundreds of years ago.

A moving memorial to the fallen and missing from WWI trenches.

The site where one of the most famous poems of World War I was composed is preserved to honor the legacy of the work.

This memorial museum chronicles the apocalyptic destruction of the First World War.

A 14th-century fortified keep showcases the masterpieces of an ingenious 20th-century clockmaker.

Most prolific publishing house in the 1600s open to the public.

A triumphant marble and bronze fountain depicting a 15th-century Hungarian king and his hunting party.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

This 19th-century prison once held Irish revolutionary Constance Markievicz, writer Frank O’Connor, and a nine-year-old pickpocket.

Horse cemetery on the grounds of Blarney Castle.

The block of aged dairy is probably still edible after 2,300 years in a peat bog.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

Housed in a memorial lighthouse, this museum relays the history of surfing, beginning with the antics of royal Hawaiian teenagers.

A tunnel with windows, so you don't miss out on the impressive views.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

This otherwise ordinary close on the Royal Mile constituted the end of the world for Edinburgh’s poorest residents.

The fairy tale castle of the “fairy-tale king,” this was also the inspiration for Disney’s “Sleeping Beauty.”

Daily jousts and dancing barrel makers in Munich's mechanical clock.