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

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

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

Instruments, apparatus, and rare books all relating to chemistry and its related sciences.

America's first serial killer rests in anonymity.

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

One man's real life disfigurement inspired a lasting local legend surrounding an eerie tunnel.

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

An indoor miniature village and labor of love for Laurence Geiringer, a model railroad enthusiast.

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

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

Enjoy a slice while browsing the world's largest collection of pizza memorabilia.

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

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

The graffitied ruins stand hidden within the Pennsylvania woods.

A historic covered bridge is but one example of an oddly prevalent American urban legend.

A quiet, gothic haven nestled between Pittsburgh's Squirrel Hill and Point Breeze neighborhoods.

This hidden gem of a garden has one of the only surviving Victorian ferneries in America.

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

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

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

Yo, Adrian!

This park contains a number of standing stones meant to heal and inspire.

The only way to see Pittsburgh is from the top of this lookout point, just like the ancient members of the native peoples did.