The oldest farmer's market in America is so ancient it was approved by the King of England.

This Old Testament garden features 100 plants from biblical times.

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

The first American department store, and home to the largest operating musical instrument in the world.

The oldest surviving botanic garden in the United States.

A clone-tree in Washington Square Park sprung from seeds that went to the Moon and back.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

Over 100 concrete munitions bunkers are all that remain of a Pennsylvanian village seized by the US government.

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

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

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

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

In the early 1800s, surgery was also a show.

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

This church in Pittsburgh is home to the largest collection of religious relics in North America.

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 headquarters of the Fraternitas Rosae Crucis, complete with Rosicrucian pyramids, all in the Pennsylvania woods.

The universally beloved children's television figure is interred on a high hilltop in one of western Pennsylvania's oldest cemeteries.

These tourist trap caverns are said to be the former home of a legendary Pennsylvania Hermit.

This little museum in the town where zombies were born celebrates the living dead.

The United States’s oldest funicular railway glides up and down a steep Pittsburgh street.

Mutant vegetables, transgenic mosquitos, and atomic rodents span the walls of this one-of-a-kind museum.

One of the steepest streets in the United States makes an intriguing challenge for cyclists.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.