A preserved 18th century homestead in Western Pennsylvania marks the spot where the Whiskey Rebellion began.

A retired firefighter created this contraption so he and his family wouldn't die if accidentally buried alive.

This giant disembodied horse head seems to balance impossibly on its nose.

The world's third-largest crystal sphere has sat in the Penn Museum since 1927 with the exception of one outlandish theft.

The Cold War-era "underground Pentagon" is a sprawling subterranean hideaway for the Defense Department.

The final resting place of two members of the infamous Doan gang, notorious outlaws and Revolutionary War Loyalists.

The famous bell was secreted away and hidden in a church in Allentown during the British occupation of Philadelphia.

Locals call this magical moss-covered walkway the "Emerald Path."

This dramatic rail curve was once the target of a failed Nazi attack.

A tradition unlike any other, this marks the site of the annual Groundhog's Day tradition.

A daily replay of the experiment that proved the rotation of the Earth.

One of the U.S. Forest Service's only mansions is outfitted with a dinner table for floating food.

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

Erected in 1697 this Philadelphia bridge is the oldest surviving roadway bridge and perhaps the oldest stone bridge in the United States.

This stone tower marks a lookout point over the historic Washington Crossing, and maybe some buried treasure.

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

America's first serial killer rests in anonymity.

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

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

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

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.

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

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

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