This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

This quarter-mile tunnel under the Bluff in Pittsburgh bends at a 45-degree angle.

Color-coded signs direct drivers on a network of routes designed to avoid Pittsburgh traffic.

This historic Pittsburgh tennis complex is a rare example of natural red clay courts.

When oil was discovered just outside of Pittsburgh, the city became home to this regional stock market.

This spot memorializes one of the greatest plays in NFL history, unless you happen to be a Raiders fan.

The last remnants of Fort Pitt also hold the distinction of being the oldest structure west of the Allegheny Mountains.

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

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.

The last street in Pittsburgh that's paved with wood.

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.

An 18th-century Catholic church converted into an eccentric temple of music and bacchanalia.

There aren't too many operational funiculars around, but Pittsburgh has two!

Yo, Adrian!

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

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

Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

A beautiful oddities shop crammed with strange and morbid curiosities.

World's first "penitentiary," meant to be humane, drove men insane.