In this historic region, homes and churches are carved into ancient volcanic rock formations.

A flamboyant five-story building in Bulgaria resembles a crawling snail.

Hidden up a dusty track off the Georgian Military Road is this fascinating waterfall with mountainous views.

Once America's longest-manned military fort, now an abandoned hulk.

What was once a trend-setting, phrase-coining icon of architectural splendor is now a rotting, forgotten hulk.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

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.

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

The abandoned husk of a mental institution that failed to save a Jazz Age icon still sits nearly unchanged.

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

This jail which was in service for over a century is now open for curious visitors.

Current docking place of the SS United States, the fastest transatlantic ocean liner.

A tradition unlike any other, this marks the site of the annual Groundhog's Day tradition.

Behold the rickety wooden glory of the world's oldest operating roller coaster.

These beautiful ruins deep in the Pennsylvania woods are thought to have been a ski lodge or a speakeasy, but no one really knows.

The internal railway of one of the biggest steel plants in America has been transformed into a linear park with unique industrial views.

Once the "Eighth Wonder of the World," this iron railroad bridge was decimated by a tornado.

The house that Frank Lloyd Wright "(shook) out of his sleeve at will" at the age of 86.

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

A stone arch leads to a cavernous 1930s spring house tucked away in the Pennsylvania woods.

Collection of trolley cars in the woods represent one man's attempt to preserve transportation history.

This Philly cemetery is the eternal home of many famous area residents, including Rocky Balboa's wife.

Buildings that dynamite couldn't bring down were abandoned because of bathroom issues.

A train station that was abandoned by the coal industry and was later converted into a cocktail bar.