A beautiful but toxic fountain of mercury.

The fading, forgotten remains of a once bright and booming factory.

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

One of the world's largest ice festivals dazzles visitors for over a month with radiant sculptures and carvings.

An ancient stone fortress considered by many to be the eighth wonder of the world.

On the Oregon coast there is a natural hole that seems to be draining the sea.

Defying all odds, this lonely little tree found a home on a log sticking out of a Canadian lake.

The oldest (maybe) swimming pool in Iceland is a stunning oasis built into the side of a lush hill.

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

Developers built a Walmart around one family's plot and constructed a mausoleum in the parking lot.

An astounding annual light display honors the victims of one of Japan's most devastating earthquakes.

A makeshift shrine to the late rock star is still kept up on the nondescript façade outside 1 Logan Place.

An artsy hidden staircase leads to breathtaking views of San Francisco.

The crypts are so large they're basically their own underground church.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

The winter home of millions of migrating monarch butterflies.

Every December, this stretch of dusty desert road transforms into a catwalk for a camel beauty pageant.

A rotating cast of guys and dolls in front of a Washington, D.C. building.

Cryptic messages embedded in the New York City sidewalk.

These 40,000-year-old stenciled hands are older than the famous cave art in France and Spain.

There’s a hidden military meme engraved on the World War II Memorial.

The fight to make Bengali an official language started in this stunning university hall.

Spike Lee's provocative film is officially honored right where it was made, the first time a work of art was used as a secondary street name.

A beloved, quirky little fountain featuring a large frog spitting water at a naked boy.