The remnants of sheer survival in Dublin's monastery district.

This ancient sinkhole-turned-healing-pool is a treasure trove of archeological discoveries and may even be the Fountain of Youth.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

Where America's first doomsday cult awaited the end of the world.

A toxic ghost town sitting atop a massive coal fire.

A walk through the historic city center, under the streets of Seattle.

The final resting place of New Orleans' most famous voodoo priestess.

A giant Troll lurks under one of Seattle's oldest bridges.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

These old stone ruins in the Oregon wilderness were once bathrooms and are steeped in legends of murder.

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

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

An artsy hidden staircase leads to breathtaking views of San Francisco.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

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

This fertility idol of questionable authenticity inspired an iconic Indiana Jones artifact.

The innocent intentions of this monument are somewhat lost in the sculpture's muscled imagery.

Before founding the American Red Cross, Clara Barton had a tremendous humanitarian impact by locating thousands of missing soldiers.