North America's oldest quarantine facility was built in response to Philadelphia's 1793 yellow fever outbreak.

Priceless space junk on display in front of a local Dairy Queen.

A "house to which to flee" for settlers in colonial Pennsylvania.

This 15-foot tall obelisk commemorating the Philadelphia-Baltimore railroad connection sat neglected for over a century.

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

This historic furnace was once used to produce cannonballs during the Civil War.

The aggressively banal name of this underground fortress of bureaucracy does little to evoke its truly surreal existence.

A pyramid commemorates the birthplace of James Buchanan, the 15th president of the United States

Featuring the largest CinemaScope screen in Pennsylvania, this drive-in has entertained moviegoers for more than half a century.

The only statue of its kind to commemorate Washington's beginnings as an officer of the British Colonial Militia.

A legendary boxing venue and ring featured in Rocky V.

The home of possibly the least-loved U.S. president stands as a sort of unpopular Monticello.

A preserved 18th century homestead in Western Pennsylvania marks the spot where the Whiskey Rebellion began.

Memorializing an American tragedy of massive proportions.

"Where the ducks walk on fish."

Where the oil industry began.

Contrary to popular belief, this secluded statue doesn't represent Pennsylvania's founder.

A retired firefighter created this contraption so he and his family wouldn't die if accidentally buried alive.

A quirky collection of outsider art made from automobile parts.

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

Steepest flood safety railway in the entire world.

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

This shrine to McDonalds' most iconic sandwich holds a 14-foot tall burger.

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