Under a playground is a little-known sealed train tunnel that likely contains the bodies of workers trapped by cave-ins.

A beautiful oddities shop crammed with strange and morbid curiosities.

The first American axe throwing club.

The pop art icon's gravesite is broadcast 24 hours a day on his museum's website.

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

This recreation of a 19th-century dime museum is full of oddities.

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

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

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

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

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

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

The Home and murder site of the witch of Rehmeyers Hollow.

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

A park full of outsider art, created by college students studying outsider art.

Delicate Wurlitzers, creepy clowns, and The Noid all share space in this insane explosion of kitsch history.

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

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

"Dark Sky Park" is heaven on Earth for astronomers, one of the rare U.S. locations with no artificial light pollution.

Found art has transformed this Pittsburgh neighborhood into a psychedelic dream.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

House of vintage taxidermy and Steampunk sculptures in a quiet Pittsburgh neighborhood.

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

Mysterious rocks that ring musically when struck.