A 19th-century smallpox cemetery is being reclaimed by scrub forest and sand dunes.

The railroad tunnel nicknamed the "Bloody Pit" for taking the lives of hundreds during its construction.

Inspiring Herman Melville and Henry David Thoreau, Mount Greylock in western Massachusetts is the highest point in the state at 3,491 feet above sea level.

This stimulating sex toy museum is sure to arouse the interest of its visitors.

A cave dwelling that was started by the Celts, expanded by monks, and finished by knights.

A vintage penny arcade hidden in the back of a fun fair-themed bar.

The rotting skeleton of a shoreside fun fair that was destroyed by fire and storms still haunts the Brighton ocean view.

These fantastically named natural pools look like something out of a Scottish myth.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

A kaleidoscopic warehouse-maze of handmade neon signs.

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

Hundreds of dwarf beeches create an unusual, haunting forest in the north of France.

These crumbling Nazi artillery bunkers are now fair game for massive graffiti projects.

The post-apocalyptic remnants of a bucolic town ruined by a plane crash.

A tiled, multi-level garden of survival in Lyon.

This ancient theater was once the home of fierce gladiatorial battles.

An isolated 17th-century chapel on a remarkable site once dedicated to Celtic sun worship.

A self-built mosaic house and sculpture park.

This collection of French root art looks like an indoor fairy wonderland.

A medieval church with largest and oldest collection of Renaissance frescoes in France.

One woman's decades-long obsession with the "La Fée Verte."

Ivy-covered Medieval tunnels cut through this charming town in France's Loire Valley.

A medieval military street hidden beneath a charming French fishing village.

This structure atop a craggy cliff in one of the most beautiful parks in Paris boasts an unbeatable view.