Along the banks of the River Rhine lies a park that seems unassuming, but beneath the surface lies a long and fascinating history.

Hilltop monument to the victory of a new nation in the Franco-Prussian War.

This marvelous array is one of the largest collections of mechanical instruments in Europe.

An ancient Roman temple hidden in the basement of Römerpassage, a modern shopping mall.

A historic casino where Dostoyevsky is said to have lost it all on a single spin of the roulette wheel.

The world’s largest museum dedicated to mining, complete with an underground show cave.

While you wait to cross the street at a traffic light in Mainz, you might notice that the light is staring back at you.

A rare water-powered funicular, it uses a huge tank of water and gravity to do its work.

This tremendous timepiece was once the largest cuckoo clock in the world.

These unusual rooms on wheels are holdovers from the 1960s.

The site of the daring river crossing that changed the course of the American Revolution.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

Formerly the world's largest, this Willy Wonka-esque contraption runs 24/7.

This incredible collection of vintage pinball machines can be played at 25 cents a pop.

A historic covered bridge is but one example of an oddly prevalent American urban legend.

Take in some Air Force history—and ogle some beautiful planes—at this little-known park near Myrtle Beach’s seashore.

If Myrtle Beach is the mini golf capital of the world, this is its crowning glory.

This maze-like, oceanfront gift shop—the nation’s largest— has been serving kitsch to the Myrtle Beach community for over 80 years.

This stone tower marks a lookout point over the historic Washington Crossing, and maybe some buried treasure.

One of the world's largest model railroads is a mind-boggling achievement.

The "world's biggest dinosaur" once housed a creationist museum in its abdomen.

The sun acts as a key that only fits this giant keyhole twice a year.

A New Jersey state park that was once Napoleon's brother's sprawling estate.

Marie told fortunes from her small stand on the Boardwalk for decades, including to a young Bruce Springsteen who would busk outside her booth.