The site of Paul Revere's historic two lantern warning.

The site of America's first commercial oil well essentially disappeared after the town went bust.

Could it have picked a better place to land?

The legacy of baseball great Roberto Clemente is preserved in a retired Pittsburgh fire station.

The largest clock face in the United States is twice the size of Big Ben and infinitely more ad-sponsored.

Where the oil industry began.

This picturesque stream was up until recently the site of a ten story mountain of slag and sewage.

Golden and naked, the figure that was once the highest point in New York is all that remains of the second Madison Square Garden.

A dramatic, 360-degree recreation of Pickett's Charge in the Civil War.

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

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

Yo, Adrian!

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

Steepest flood safety railway in the entire world.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

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

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

This Old Testament garden features 100 plants from biblical times.

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

Once the "Eighth Wonder of the World," this iron railroad bridge was decimated by a tornado.

A restored Pittsburgh house of God has been converted to a marvelous house of suds.

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

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

The first American department store, and home to the largest operating musical instrument in the world.