A formerly glacier-tipped volcano that inspired none other than Jules Verne.

A trio of hidden hot tubs takes advantage of Iceland's natural geothermal vents.

The Icelandic Sea Monster Museum explores the area's history of aquatic cryptid sightings.

Walk in the footsteps of the gods and straddle two tectonic plates.

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

A stunning, two-tiered waterfall made famous by poets, artists and the legend of a ghost dog.

A once grand hotel is being retaken by the wilderness it once capitalized on.

The world's largest kaleidoscope, designed by a 1960s psychedelic artist.

Collapsing castle on the Hudson river was once the storage site of military surplus business.

A sulfuric martian landscape that looks far better than it smells.

A massive sea stack famous for its appearance in The Goonies.

Only known mainland rookery of the threatened Stellar sea lion.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

On the Oregon coast there is a natural hole that seems to be draining the sea.

World's first "penitentiary," meant to be humane, drove men insane.

This abandoned ironworks was once the most important military supplier in America.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

Reclaimed by nature, the ruins of Doodletown, New York are remnants of a town consumed by a state park.

A crumbling hospital from the 1850s on Roosevelt Island.

A former insane asylum despised by Nelly Bly and Charles Dickens is now fashionable apartments.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

This once-grand marvel of engineering is now 41 miles of scenic hiking trail.

A ruined mansion hidden in the woods of the Hudson Valley, home of a tragically doomed romance.

Medicinal spa created with the discharge from a geothermal energy plant.