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

Rustic natural hot springs in the deciduous rain forest.

Home with Gothic windows featured in a famous painting.

Winding paths and ramshackle mausoleums in the oldest "park cemetery" in London.

Mexico's astounding mummy museum with "the world's smallest mummy."

Ample proof that watery ends make for well-preserved, millenia-old mummies.

Iron Age "bog person" preserved for over 2,300 years.

Thousands of exquisitely carved stone water storage wells, hundreds of stone steps fill this exquisite medieval stepwell.

Paranormal activity on the great lakes.

An optical illusion found amid a logged redwood forest.

The largest catacomb system in the world.

Three bridges straddle a stream, one stacked upon the other.

42nd story Pyramid shaped penthouse tops Seattle's oldest skyscraper.

North America's first frozen mummified remains of an ice age steppe bison, the 36,000 year-old mummy named "Blue Babe."

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

The clock that sets them all.

An abandoned aircraft sits submerged in a lake in the Alaska wilderness.

A number of gruesome unsolved murders have turned this simple home into a morbid tourist trap.

This 80-year old mannequin is so lifelike it is believed to be an embalmed corpse.

A fiery crater has been burning in the Karakum Desert since 1971.

The tallest sea cliffs on the Southern Hemisphere are a climber's worst nightmare.

The Dalai Lama named this New Zealand landscape the "Spiritual Center of the Universe."

The real life Hobbiton, this sheep farm has been forever transformed since being built for The Hobbit film series.

The world's only complete colossal squid specimen is on display at the Te Papa Museum.