World War II bunker still standing on the New Jersey beach.

Decommissioned NYC subway cars are dumped into the ocean to create this underwater wildlife habitat.

Welcome to old Florida, where a 1940s mermaid show is still enchanting visitors.

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

Possibly the most beautiful carillon in the world, set atop Iron Mountain in Florida.

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

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

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

An abandoned stretch of highway, deteriorating next to the operational one.

The ghostly remains of an accidental sea.

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

A simple midtown bar was once the home of a secretive and exclusive club staffed by "bunnies" under Hefner's strict rules.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

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

One of only two commuter aerial tramways in the United States.

A crumbling hospital from the 1850s on Roosevelt Island.

The fairy tale castle of the "fairy-tale king."

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

A clock set into the concrete outside a Manhattan jeweler has been telling time underfoot for over a century.

Once the tallest building in the world and the site of "the highest dinner ever held in New York" this building now holds the most expensive penthouse in the city.

Visit the site of a subway powered by nothing more than air--and lots of it.

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

Pennsylvanian mass grave and possibly mass murder.

In which a local geological marvel becomes a quaint roadside attraction.