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

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

This restaurant offers a side of antiques, curios, and a bathroom chock full of owls.

One of the last remaining movie theatres in the country that features a rear-projection system.

The oldest Italian café in Boston, this spot also serves as a veritable museum of vintage coffee ephemera.

This plaque marks a place where one of Hollywood’s most famous dancers got his start.

Nothing says indulgence like a 1,500-pound chocolate castle.

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

A portion of the old Pirates stadium over which a defining home run once flew still stands even after the rest of the stadium was torn down.

"Where the ducks walk on fish."

Once the most painted on object in the world, this short campus fence is well on its way to being so again.

The abandoned coal loading dock is a canvas for unsanctioned art.

Hundreds of protractors affixed to surfaces all over the city.

An Irish Memorial commemorating those who perished due to potato blight.

This dramatic rail curve was once the target of a failed Nazi attack.

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

Long hidden under grime, the politically radical murals of a little known Yugoslavian master are finally getting their due.

A local prank turned town icon.

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

First a root beer ad, then a golf course clubhouse, and finally a massive teapot.

This spectacular public market has got meat, fish, vegetables, baked goods, and enough kielbasa for a lifetime.

Funded by John D. Rockefeller, this is one of the earliest, and most beautiful, shopping arcades in America.

This claimant to the title of "smallest church in the 48 states" doubles as an equally tiny, quasi-post office.

Museum dedicated to awful artwork.