Iceland's largest geothermal mud pool is a little bit haunted and a little bit dangerous.

Medicinal spa created from the mineral-rich runoff of a geothermal power plant

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

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

Three columns of volcanic rock shoot out of the ocean.

An ode to one of the first concerts broadcast via satellite.

A unique set of caves that spits waves back out into the ocean.

Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.

More than 2,000 species of tropical plants call this nature preserve and sanctuary home.

Hide from the tourist hordes in these relatively unknown, and unguarded lava caves.

This legendary urban waterfall creates a dazzling display of rainbows.

Quite simply the largest tree in the world (by volume).

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

The wild west is still alive and well at this authentic mining town watering hole.

Brightly colored 30-foot-tall totems light up the desert sky just outside Las Vegas.