A sinuous path among steep cliffs creates a stunning sight in southwestern Serbia.

What was once a bustling mining installation is now a bustling hub of contemporary art.

This bike path was sunk below water level for maximum wonder.

The entrance to this Frankfurt subway station looks like an old tram car crashed into the concrete sidewalk.

The busy transport hub is home to the tallest airport slide in the world.

Nine nice parcels of land along a flight path offer a quiet respite... until a plane soars overhead.

Located in the remote Monitor Valley, this travertine bowl contains a scalding pool of water.

Crossing this suspension bridge feels like walking through the sky, a fitting tribute to the head of the Apollo program.

Ride a boat through this magnificent underground world, which now doubles as a theater.

A mile-long navigable cave adorned with stalactites and stalagmites reaching up to 65 feet tall.

The largest cave shaft in the world is home to thousands of birds and popular with BASE jumpers.

A spring water stream jumps through a walkable "bridge" cavern and a narrow canyon.

If there's another drive-through golf-cart bar in a bat-filled cave on top of a mountain, we don't know about it.

Alien rock formations grown from the sands of an Australian national park.

Dinosaur eggs were first discovered at these fiery red cliffs.

One of the most extensive and well-preserved collections of dinosaur footprints in North America.

A trail of footprints discovered after a landslide was left not by the Devil, as originally believed, but by an early human ancestor.

Its eclectic exhibits range from the world’s first motorcycle to Luke Skywalker’s Land Speeder.

The last street in Pittsburgh that's paved with wood.

Home of Howard Hughes' Spruce Goose.

This former Soviet military base has over 10 original aircraft and an enormous amount of memorabilia on display.

Approximately 300 million years ago, a massive coral reef existed in what is now the largest limestone cave in Japan.

One of the world’s largest cave systems houses legends, concerts, and wondrous rock formations alike.

This dreamy street will transport you to wintertime in Victorian England.