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

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

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

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

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

A piece of baseball history is preserved in a Pittsburgh parking lot.

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

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

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

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

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

The largest university building in the West is a gothic masterpiece containing dozens of theme rooms based on different countries.

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

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

A stone arch leads to a cavernous 1930s spring house tucked away in the Pennsylvania woods.

Berkeley Springs State Park boasts the nation's only monument commemorating presidential bathing.

The antique hotel still has a jail in the basement, though the cockfighting ring is long gone.

This beautiful stone arch bridge wasn't even expected to stand for one day, but people have been crossing it for centuries.

A larger-than-life statue of America's favorite sundae marks the place it was invented.

Pennsylvania's own Roswell-style UFO mystery.

This Art Deco service station has been providing tune-ups and turning heads for close to a century.

This titanic java kettle is one of the many kitschy landmarks located along America's OTHER famous highway.

A dozen U.S. presidents have stayed at the historic resort, which was known as James Buchanan’s “Summer White House” from 1857-1861.

This morbid, delightful curiosity shop offers everything from animal bones to human teeth.