Beneath Denmark's Højbro bridge, a bronze merman and his seven sons forever mourn for the mother and wife who left them for land.

Did he come up with a theory of cosmic-ray showers while sitting in this bath?

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

Once a meeting point for great thinkers, and the midpoint of the country.

Long before ultrasounds and modern testing, medical specimens like these conjoined twins helped physicians learn about congenital anomalies.

This pair of gilded girls atop an Art Deco building in Copenhagen were built to function as a weather indicator.

The traveling wares of Denmark's most famous author.

The original "capsule building" is a masterpiece of Metabolist architecture.

Stepping away from the glitz of mobsters and casinos to learn about the other history of Vegas.

This arid landscape was once a lush wetland. Today, it's a paleontological site filled with fossilized mammoths, sabertooth cats, and more.

This once-booming Gold Rush town is now home to a herd of feral donkeys.

A planet-hunting astrograph built in the 1920s to seek out the so-called "Planet X" beyond Uranus.

Under the right conditions, rocks will move across this dry lakebed, leaving trails behind them.

These markers are used to determine the ground stability of the Strip.

“Live hard, ride fast, eat pizza” at this joint filled with Evel Knievel memorabilia.

The best Tiki bar in Las Vegas.

A blast of nostalgia awaits visitors to this miniature indoor raceway.

Back in 1952, you could get a mushroom cloud chaser with your atomic cocktail.

The eerie ruins of an isolated abandoned town nicknamed "the Widowmaker" for its deadly gold mine.

This Las Vegas casino boasts one of only three spiral escalators in the United States—an engineering wonder.

An overlooked monument to the celebrity gangster who helped put the sin in Sin City.

An exotic wildlife habitat right off The Strip.

Thousands of artifacts relating to human sexuality, including the world's largest sex bike.

This crumbling Death Valley mining complex was known for its use of giant, 20-mule team wagons.