This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

Once a prosperous mining village, this tiny Taiwanese town is now overrun with cute cats.

Now an entertainment complex, the Lingotto building was once an avant-garde auto factory with a test track on the roof.

The gilded vestiges of a sterling department store can still be found in a Brooklyn shopping center.

This intricately spiralling forest was created as a monumental work of art.

For a couple of months each year this Swedish city turns into a festive neon phantasmagoria.

A stray meteor left this picturesque hole in the Australian outback.

The third version of this tall sailing ship sits, rusted and burnt, in Lake Ontario.

This odd Chilean waterfall-cano hotel must be entered via a rope bridge.

These disused steel furnaces are now haunting ruins that may one day be a national park.

Natural stone arches form a walkable "cathedral" at low tide, then disappear entirely when the water returns.

This elegant arc of a waterfall marks a religious turning point.

The graffiti-covered remnants of a former triangulation station are balanced precariously on this California peak.

Malaysian fireflies create a dazzling display as thousands light up in unison.

This abandoned asylum was once a state of the art facility before devolving into one of the most deadly mental institutions in American history.

This Tennessee manse was built so opulent that the very utilities doomed it to fail.

The titular "little arch" near this Italian resort is one of the most popular diving spots in the country.

These World War I shooting range tunnels are now haunted halls of underground graffiti accessed through the roots of a tree.

At first glance, little checkered structures on the hillside look like they house the living, not the dead.

A crumbling stone stable and carriage house are all that remain of a manse that was once filled with Egyptian artifacts.

One of the ghostly stops along Route 66.

Located on 420 acres in the high desert, this spiritual center is dedicated to the "science of the future."

On a barren hillside in the Yucca Valley, the recently restored Desert Christ Park has attracted pilgrims and kitsch hunters for over 50 years.