This cavernous abandoned marble mine is popular with ice skaters in the winter.

A functioning Roman-era aqueduct and bridge in rural southwest France.

This French castle is said to have once held the Holy Grail but is now a gorgeous mountaintop ruin.

Trek into the depths of the cave where 17,000-year-old paintings exist alongside 400-year-old graffiti.

15,000 year old bison sculptures.

One of the shortest streets in York has an especially odd name.

Follow the original medieval paths that wind through this intriguing section of the city.

A mosaic-tiled house built by graveyard sweeper Raymond Isidore.

An intact, still operating pharmacy from the 18th-century filled with numerous artifacts and paintings.

This Renaissance square was at the center of Leonardo da Vinci's map, the first ichnographic ever.

This castle was once the home of one of the most powerful women of the Renaissance.

The largest cave chamber in Britain—big enough to fit a whole cathedral inside.

A group of glacial erratic boulders are improbably balanced on white limestone pedestals.

The ruins of an ancient Celtiberian town with incredible rock-cut buildings and a Roman aqueduct.

The ancient tomb acts as a calendar that keeps perfect time.

This Neolithic passage tomb forms part of a World Heritage Site.

A small island abbey is the final resting place of many medieval Scottish monarchs, including the real Macbeth.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

The world's oldest optical museum is an odd collection where the exhibits look at you.

The world's oldest family-run magic shop is hidden beneath a bustling London thoroughfare.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

This shop and gallery is a modern-day cabinet of curiosities, unassumingly positioned along an urban thoroughfare.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

A slightly surreal menagerie of structures that were lovingly spared from demolition and reconstructed in a field.