Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

The most powerful waterfall in all of Europe.

Climb right into the heart of this colorful Iceland volcano.

Iceland's largest lagoon is home to stunning multi-colored icebergs.

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

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

This fantastical waterfall is hidden in a cave located in a cracked cliff.

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

The unique waterfall in Iceland's south features a backdrop of geometric black lava columns.

No one's quite sure why there's a metal megaphone bolted on two rocks in the middle of the Mojave Desert.

Walk over a 150 year old manhole.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

The oldest house in Manhattan is now a museum that remembers the home's sordid history of scandals, vice-presidents, and ghosts.

The loneliest island in New York.

Abandoned power station once home to a squatter community, now being developed into an arts center.

A long abandoned hospital building on the outskirts of NYC.

Read between the lines of the subway map to find the hidden abandoned Civil War fort.

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

First a horse rendering plant, then a 19th century landfill, this beach is full of glass from thousands upon thousands of broken bottles.

The name of this famed hospital was once a byword for the horrors of medical and psychiatric care.

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