The hippo that stands on this university campus was once a drunken flea market purchase.

A priceless collection of the Nation's cryptologic history.

Instruments, apparatus, and rare books all relating to chemistry and its related sciences.

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

South Philadelphia is home to Keith Haring's only surviving in situ collaborative public mural.

This jail which was in service for over a century is now open for curious visitors.

A local prank turned town icon.

Pennsylvania's own Roswell-style UFO mystery.

The only way to see Pittsburgh is from the top of this lookout point, just like the ancient members of the native peoples did.

A clone-tree in Washington Square Park sprung from seeds that went to the Moon and back.

A museum dedicated to the strange and extravagant costumes and memorabilia of the mummers, a tradition older than Philadelphia itself.

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

The world’s first penitentiary, meant to be humane, drove men insane.

A unique marker erected during the 18th century.

The maritime museum that boasts the largest nautical library in the western hemisphere.

The location where the American Revolution ended.

Dedicated to the man who created the first radio wave communication system.

A family agreed to sell their property to Disney on the condition that this tree, planted as a wedding gift, would not be removed.

The famous animator's private station house and man-cave was the birthplace of imagineering.

Deep into the lower floors of Pike Place, find a date with fowl fate.

Now a public art piece, this curious metal feature originally advertised a tinsmith's services.

This giant roadside fruit is home to an array of apple-based treats.

The longest enclosed pedestrian bridge in the world spans 14 lanes of traffic and six rail tracks, all while lighting up the night sky.

This colorful creation wasn't always a welcome part of Toronto's Moccasin Trail Park.