Board a mine car and descend the #190 slope 300 feet underground into the Clark Vein of coal.

Pennsylvanian mass grave and possibly mass murder.

This Pennsylvania cave holds evidence of the oldest known inhabitants of North America.

These disused steel furnaces are now haunting ruins that may one day be a national park.

It would take 35 firetrucks to fill this enormous glacial pothole.

This secluded walking trail is a hidden gem of a Pittsburgh park.

The largest university building in the West is a gothic masterpiece containing dozens of theme rooms based on different countries.

The Pennsylvania landscape depicted by a quarter mile of mosaics made from used road signs.

This lush forest valley was once mined for lumber to the extent that it was once nicknamed "The Pennsylvania Desert."

The ruined remains of a coal mining ghost town are hidden within the woods.

When the Austin Dam failed it destroyed much of Austin...and then it failed again.

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

There aren't too many operational funiculars around, but Pittsburgh has two!

This semi-spooky remnant of an abandoned hotel provides fantastic views.

A failed piece of Orientalism has become the proud symbol of a community.

A macabre farm reserved part of its 222-acres for dead bodies, all in the name of science.

This little-known Revolutionary War fort is supposedly haunted by the ghosts of its past.

The remains of a community that was forced to move for a dam that never materialized still rot in this Pennsylvania park.

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

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

A museum dedicated to the strange and extravagant costumes and memorabilia of the mummers, a tradition older than Philadelphia itself.

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

In the bowels of a 19th-century brewery lurks a fine-dining restaurant offering an array of themed feasts.

This public space is speckled with the eerie remnants of a defunct amusement park.