Sections of the iconic limestone columns have been left uncleaned as a reminder of the city's polluted past.

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

Learn about the history and craftsmanship of carousels inside this museum located in a former post office.

An ode to filmmaker George A. Romero, who used the mall to film an iconic horror movie.

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

The Pennsylvania shopping center was once the setting for the 1978 film, "Dawn of the Dead."

A retrofuturistic art installation in the Pittsburgh Airport.

Where the "World Pinball Champion” is crowned.

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

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

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

Despite its lavish ornamentation, and wholesome lifestyle of its devotees, this mountain commune has faced its share of issues.

Deep scars on the earth left by the Ice Age.

Japan's corrupt-mental-institution themed restaurant offers diners a chance to eat inside of filthy cells.

See no evil, hear no evil, speak no evil.

Is this cat asleep or just pretending?

A grandiose title could not save this mercantile community from obscurity.

This campus museum commemorates a national tragedy.

Memorials and tributes scattered across the university grounds remember a famous national tragedy of the Nixon era.

For decades, this waterfall remained hidden because of an artificial dam.

In a small Japanese garden off a busy Denver street, a memorial to a brave, principled politician.

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

Look closely and you’ll notice that the color changes a third of the way up the tower.