A rare chance to get up close and personal with a 13-mile ribbon of ice near downtown Juneau.

This small city where almost everyone lives in the same building can only be reached via North America's longest tunnel.

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

The king of U.S. high points towers over every other peak on the continent.

Mind-blowing carvings and fantasy ice scenes grace the largest year-round ice environment in the world.

An autonomous oak in Alabama.

This space rock fragment is one of the only meteors to have ever struck a human.

The highest point in Alabama was almost completely deforested, but is now home to protected towers and trees.

Famous for its bio-luminescent inhabitants, known as "dismalites."

148 feet long and in the middle of a verdant forest.

One person's lost luggage is another person's treasure.

This "floating island" plateau sits 7,671 feet above the forest floor.

This everlasting lightning storm may be the world's largest generator of ozone.

This small oxbow lake has rare giant river otters and some Seussian-sounding birds.

The highest tropical mountain range in the world is in Central Peru, home to a vast array of exotic and quirky plants and animals.

The world's largest clay lick, where parrots gather to snack.

One of the world's tallest waterfalls wasn't revealed to the world at large until 2006.

This Peruvian canyon is filled with geometric salt pools that have been being harvested since the Incan empire.

Extraordinary rock formations in open Peruvian fields.

An unexpected desert oasis in South America.

Huge stone depressions which may have acted as an Incan agricultural experiment.

The Uros people live on floating reed islands in lake Titicaca.

A remarkable geological formation resembling a forest made of stone.

A set of ancient drawings in the desert of Peru that are so massive, many of them can only be fully seen from the sky.