The seamy, underground secrets of Portland's criminal past.

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

A 140-year-old castle with underground caves hidden in San Francisco.

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

Giant Redwood-themed cafeteria operates under the golden rule, "Dine Free Unless Delighted."

Mother Nature outdoes herself with this stunningly beautiful set of caves carved into marble.

Remants of foundations, streets, and streetcar tracks inhabit the cliffs where a landslide occurred in 1929.

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

An enormous, inside-out glass globe built in 1935.

Remnants of a storybook amusement park hidden behind a strip mall.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

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

The ghostly remains of an accidental sea.

A swing to dangle you off the very edge.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

The inspiration for H.P. Lovecraft's horror stories and Batman's Arkham Asylum is now a condominium complex.

A 16th-century horror show built in a lovely Italian garden.

A toxic ghost town sitting atop a massive coal fire.

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

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

The legendary building that needed ghostly approval before being built.

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

The sound of swaying stalks in this stunning grove has been named a governmentally recognized sound.

An ancient capital city that dates back 3,000 years old and harbors many surprises.