The longest continuous lava tube in the continental U.S. offers 2.5 miles of dark explorations for the adventurous.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

Panorama exhibition hall in old silent theater with a beautiful backyard garden.

A natural gas leak provides a flickering flame beneath a waterfall.

Resting place of Hollywood's immortals is also site of summer film screenings.

Once the most densely populated place in the world, this island is now a ghost town.

World War II-era Nazi compound nestled in the Santa Monica hills.

A 30-acre garden inspired by the principles of modern physics.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

Pompeii's less famous neighbor is still revealing her secrets.

Furniture tries to escape an abandoned building in San Francisco.

A hotel and restaurant serving as the mecca of kitsch.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

An abandoned facility that has become a place of ritualistic satanic worship, or so rumor has it.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

An Aztec snake god has taken the material form of an apartment complex.

These fantastically named natural pools look like something out of a Scottish myth.

One man's homage to the sun continues to grow like a glass fractal.

Hollowed out cedar log tubs set in an ancient towering forest.

Ruins of a German Castle on top of a towering stone pillar.

In this historic region, homes and churches are carved into ancient volcanic rock formations.