This remote camping site offers incredible stargazing opportunities.

The New York hotel where tragic visionary Nikola Tesla spent his final hours, destitute and alone but for the pigeons.

An underwater restaurant, surrounded by a coral reef.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

A luxurious doomsday bunker hidden beneath an unassuming Las Vegas home offers the best of subterranean suburbia.

There is an unmarked red button hidden over Houston's Buffalo Bayou that is just begging to pushed...

A taste of Middle Earth, in the middle of the Bayou City.

An unrealized Taoist palace left abandoned in a Houston suburb.

Nestled in the heart of a Texas town is a dreamy secret garden dating back to the 1940s.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

A 17th-century doorway in a small Sabine village is a portal into the mysteries of alchemy.

An ethereal glowing blue ocean cave in Croatia.

A mysterious echo seems to defy the laws of acoustics.

An acoustic anomaly with a mysterious cause.

This scale model of our solar system hid in plain sight for years before a physics team sought out all the planets.

Humble beginnings for one of the world's most famous scientists.

Dive for drinks at Croatia's first and only underwater winery.

Colorful concentric circles honor a small Croatian town's supposed spot at the nucleus of it all.

Longest fortress system anywhere in Europe.

Sunset-colored dunes of volcanic ash make taking a poor photo impossible.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

The oldest stone house in Paris was built by its most famous alchemist.

Introducing the Green Fairy to her fawning masses.