This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

The remains of the iconic train crash from the movie The Fugitive can still be found rusting along the Great Smoky Railroad.

For 20 years, this whale skeleton has been slowly dripping oil on the floor of the museum where it hangs.

Limestone caves with spectacular showcase chambers.

One of the largest, oldest, darkest, quietest motel rooms in the world.

The largest natural travertine bridge in the world is nestled in a small canyon in central Arizona.

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

Eons ago, a rushing lava river formed this pristine passage through solid rock.

In a 345-million-year-old cave that's 200 feet underground, dinner awaits.

Home to the world's oldest wooden building.

Sweden's oldest street has not changed for nearly a millennium.

Nepal’s last remaining population of wild water buffalo and many other rare species call this reserve home.

This precariously perched fortress was once ruled by a crow-worshipping baron.

On a quiet suburban street stands a peculiarly decorated house covered in mosaics.

In a city filled with Frank Gehry buildings, one stands out as one of the architect's weirder works.

An increasingly eccentric apartment building, topped with winged beasties.

The words of the neighborhood's most famous poets adorn four concrete walls.

After starting as a whimsical tourist attraction that eventually found its way to ruin, these renovated canals offer a lush and exotic locale on the Pacific Coast.

Smooth basaltic rocks tell a tale of ancient glacial waterfalls.

Ancient human, animal, and geometric figures drawn in the earth.

Massive prehistoric mammals used these stones as oversized scratching posts.

An extensive collection of ancient Egyptian artifacts and mummies.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

Detailed facade of a brownstone in Boerum Hill.