A once-glowing grotto at the bottom of Waikapalae Wet Cave.

A series of waterfalls and pools that flow through the 'Ohe'o Gulch and into the ocean.

Race through the maze, get your name on the sign.

A beach made of semi-precious green sand on the Big Island of Hawai'i.

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

This black shoreline is made up of exploded lava particles.

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

A tunnel of hardened lava along Maui’s famous Road to Hana.

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

When the big city meets the edge of the frontier, log skyscrapers are born.

A spoke-tacular artwork constructed from recycled bicycle rims.

The picturesque remains of an abandoned silver mine slope down to Tagish Lake in the Yukon.

Roadside collection of 65,000 signs.

This tiny square mile of Canadian sand was once considered the world's smallest desert.

A skeletal collection of former nautical mainstays.

Locals believe the purity of this huge, untouched Arctic lake could be the salvation of human civilization.

This house of worship in the Arctic Circle is shaped like an igloo.

Natural earth mounds formed in the far north.

Ice roads, deep holes and 3,500 pounds of diamonds.

These hellish-looking cliffs in the Canadian Arctic have been burning for centuries.

A monument commemorating the role of Alaska's native Tlingit guides in the Klondike Gold Rush.

Clean, cold drinking water flows from a nondescript pipe in a roadside rock face.

The oldest original lighthouse in Alaska that was born out of a tragic shipwreck.

Impressive artifacts from Juneau's gold mining days fill this mining site-turned-museum.