A giant, Gilded Age mansion that once belonged to the beer baron of Milwaukee.

This striking art museum holds an amazing series of curiosity cabinets.

The last of Philadelphia's wood-paved streets is now a landmark of terrible engineering.

This extraordinary Depression-era expenditure was modeled after a postcard of a Mediterranean hotel.

The famous bell was secreted away and hidden in a church in Allentown during the British occupation of Philadelphia.

These lush botanical gardens employ the most purrfect pest control force.

The residents of the Neighborhood of Make-Believe live without much fanfare within the Pittsburgh Children's Museum.

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.

The sounds of the world's largest fully functioning pipe organ dazzle shoppers at a Philadelphia Macy's.

A local prank turned town icon.

This elaborate towering structure was once famed for its revolutionary height.

This meticulously extracted nervous system allegedly came from a 19th-century custodian who donated her body to science.

The first American department store, and home to the largest operating musical instrument in the world.

Once the "Eighth Wonder of the World," this iron railroad bridge was decimated by a tornado.

The universally beloved children's television figure is interred on a high hilltop in one of western Pennsylvania's oldest cemeteries.

Mural made of 100,000 pieces of hand blown glass, and until recently, the largest glass mural in the US.

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

A Hawaiian stairway to heaven—that you can't climb.

The air force base preserves its scars from the Japanese attack on Pearl Harbor.

The famous aviator's final resting place is a study in natural beauty.

This black shoreline is made up of exploded lava particles.

A suburban street in Anchorage doubles as a runway, and each home has its own airplane hangar.

This whimsical stacked cabin looks like something out of a children's book.