This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

A museum dedicated to exhibiting remarkable outsider art.

Yo, Adrian!

Dr Barnes' $25 billion private collection of art and arboretum.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

Trace the history of the nation’s early days at the site of America’s oldest stock exchange.

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

This overlooked courtyard and museum celebrate Benjamin Franklin's life and achievements.

This beloved marketplace mascot poops money and grants good luck.

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

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

Huge masonic hall in Philadelphia with lavishly themed rooms.

This vintage short line in Amish country runs passenger steam train excursions and still hauls freight.

A huge railroad museum with over 100 pieces of rolling stock focusing on the railroad history of Pennsylvania.

Don't get it twisted: This is the oldest pretzel bakery in the United States.

This museum focuses on the history and culture of the German settlers in Pennsylvania.

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

This Pennsylvania structure, the oldest building in Gettysburg, was once a stop on the Underground Railroad.

Experience the pivotal Civil War battle at this interactive museum.

A dramatic, 360-degree recreation of Pickett's Charge in the Civil War.

North America’s largest collection of horological devices and home to a colossal clock with a dizzying array of features.

The remains of the great moral philosopher reside in a university in London.

The Tudor-style cottage in the middle of the square is not quite what it seems.

On October 17, 1814, a 15-ft. wave of beer ran rampant through the streets of London.