This stunning mass of ice spans 121 square miles and is still growing.

A modern artist's primitive stone faces and unique rock instrument join Iceland's terrain with its history.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

Preserved Inca city and site of the last Inca stronghold against the Spanish conquistadors.

The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

Three and a half miles of cliffs, rocky beaches, Gilded Age mansions and 40 Steps to nowhere in particular.

A museum dedicated to the alleged Roswell Incident.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

A small metropolis of Pueblo cave dwellings have been carved right into the hillside of this national monument.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

A beautiful geyser under environmental threat.

An underground city of salt.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

Real bones which are said to have belonged to a Polish dragon.

This man-made mound monument was built out of soil from all across the Polish empire.

A place where the laws of nature seem to have gone completely berserk... but of course haven't.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.