Contrary to what one might expect, ice forms inside this small cavern during the summer and melts during the winter.

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

A local prank turned town icon.

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

This elaborate towering structure was once famed for its revolutionary height.

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

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

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

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

An outlandish shoe shaped house built by an eccentric millionaire.

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

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

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

Pennsylvanian mass grave and possibly mass murder.

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

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

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

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

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

This eerily well-preserved coal town was saved from destruction by a Sean Connery movie.

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.

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

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