Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

A 18th century graveyard and its astonishing cortege of macabre iconography.

For those with no fear of heights: a skywalk 4,700 feet up on a Chinese mountain.

Limestone caves with spectacular showcase chambers.

Large Hadron Collider and the Birthplace of World Wide Web.

A grotto-like lodge decorated with gilded mosaics, rocks and a noisy waterfall was the setting for the most sumptuous pleasure house of 1900s Europe.

An isolated village literally built into the crevices and rock formations of a mountain.

Mile-long cave system near Great Smoky Mountains.

Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.

This one-time health resort was used by aristocrats around the world.

A stunning silver lining to global warming's gloomy cloud.

This innocent-looking townhome is actually a subway exit.

This chilly Canadian hotel has a four-month lifespan due to the unusual material it's made of.

Wonderland replication in progress by one persistent man.

Moss and stone turn this waterfall into an otherworldly liquid veil.

Ten 25-foot-tall, beehive-shaped kilns, abandoned in Death Valley.

Each year melting snow turns these Austrian hiking trails into scuba zones.

This immaculate and historic water garden culminates in a massive stone dining table with an inset fountain for chilling the wine of the Cardinal's guests.

This naturally heated mountainous creek has created a group of neon blue pools of potentially deadly boiling water.

Beijing's expansive subterranean hiding spot now crumbles away as a tourist destination.

1,001 carved statues of the Buddhist God of Mercy, each with a unique face.

A legendary speakeasy bookstore returns from the brink.

The one-time stronghold of the noble Douglas family, now home to ghost sightings and nesting birds.

When the rain falls, this drain system turns into a musical instrument.