Inside this 150-year-old barn turned antique shop is a vast array of items for curios hunters.

One Pittsburgh musician's decades-in-the-making memorabilia collection is on display at this rock-n-roll curio shop.

A curious building honoring past and current members of a historic musical comedy troupe.

The Cold War-era "underground Pentagon" is a sprawling subterranean hideaway for the Defense Department.

A legendary boxing venue and ring featured in Rocky V.

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

For decades, it has disappeared and reappeared as water levels rise and fall.

A unique workspace where offices reside on pirate ships and inside gingerbread houses.

This forgotten building was one of the few Philadelphia-area breweries to survive Prohibition.

Alexander Hamilton’s creation caused quite a bit of controversy.

Steepest flood safety railway in the entire world.

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

An almost life-sized elephant named Ms. Ellie greets visitors at this jumbo-themed museum.

The mortal remains of a Russian prince, priest and paranormal investigator who came to America in 1792.

The body of St. John Neumann and his collection of hundreds of relics, on display in a Philly church.

This icon of the Atomic Age now lays dormant.

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

Contrary to what one might expect, ice forms inside this small cavern during the summer and melts during the winter.

Step into a pastel time capsule where candy is truly dandy.

Behold the rickety wooden glory of the world's oldest operating roller coaster.

This huge, disused viaduct is now a crumbling concrete underworld of covered in years of graffiti.

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

This museum boasts a bucket of teeth and tells the tale of a 20th-century dental circus.

One man's real life disfigurement inspired a lasting local legend surrounding an eerie tunnel.