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

Huge masonic hall in Philadelphia with lavishly themed rooms.

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

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

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

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

A failed piece of Orientalism has become the proud symbol of a community.

An outlandish shoe shaped house built by an eccentric millionaire.

Meet your friends, marry your true love, or tell your enemies to kiss your butt under this historic Pittsburgh timepiece.

A model of a dinosaur that was named for Andrew Carnegie stands outside the museum that also bears his name.

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.

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

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

The United States’s oldest funicular railway glides up and down a steep Pittsburgh street.

Pennsylvania's highest point is spotted with boulders which were pushed to the surface by nothing but cold.

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

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

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

Nope, not Washington Irving's house.

On this island, you suck away your garbage via an elaborate pneumatic tube system.

Manhattan and the Bronx have been playing tug-of-war over this former island neighborhood for more than a century.

Manhattan's Thirteenth Avenue was made on landfill then deliberately destroyed — apart from one small, obscure block.

Twice a day one of these tragic bronze mariners drowns with the tide to remember all those the sea has taken.