You'll need cowboy boots to trek to this old-fashioned saloon nestled in a giant natural cave.

This once-popular otherworldly landscape was formed by one of the largest volcanic eruptions in history.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

Eat your Big Mac in a DC-3.

Now overgrown, these anti-tank barriers from World War II are sometimes called "dragon's teeth."

Passengers are not allowed to set foot outside this station, but you can still enjoy spectacular views of the sea from the platform.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

The United States Capitol's former columns still stand.

One of the most acclaimed eateries in Arkansas is a two-table diner on the ground floor of a family home.

Winter weather reveals a large Italian marble crucifix drowned beneath Lake Michigan.

Thousands of exquisitely carved stone water storage wells, hundreds of stone steps fill this exquisite medieval stepwell.

A little piece of the Shire is hidden behind a plant nursery in Port Orchard, Washington.

Elevated freight railway turned wildly successful urban park.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

The only Bahá'í house of worship in North America and one of only a handful worldwide.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

A market built atop boats is one of the few floating holiday markets in Europe.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

The world’s largest Masonic temple was saved by the White Stripes.

The oldest continuously-operating tavern in Wisconsin used a clever loophole to serve alcohol during Prohibition.

A church that bred legends, and served as an inspiration for the Da Vinci Code.

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

This religious complex carved into a cliff is steeped in legends of miraculous stags and the Holy Grail.