This shallow cave got its name from copious amount of human bones found inside.

These enduring murals depicting a distinctly Marxist tribute to capitalism could not even be defeated by McCarthyism.

This national park on the shore of Lake Michigan features remarkable dunes that lie at the heart of a Chippewa legend.

One man's attempt to create an artistic wonder on a run-down block in Detroit.

The Beaux-Arts aquarium boasts a vast collection of saltwater and freshwater fish on an island in the Detroit River.

A Beaux-Arts triumph set to become Ford's innovation campus

Island where motor vehicles are banned -- home to the only carless highway in the United States.

Astounding collection of coin-operated games and automata.

The city is full of whimsical portals to another world.

An ancient Scottish rock formation said to be the gravesite of a giant remains ensconced in legend and intrigue.

The site of the first medieval crusade that pitted Christians against Christians.

It was once nicknamed "the most bombed hotel in Europe."

This Victorian-era public house has set the standard for pub-style elegance for over a hundred years.

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

This short bridge is the only thing connecting a tiny Irish island to the mainland.

Northern Ireland's Brobdingnagian stepping stones.

The ancient tomb acts as a calendar that keeps perfect time.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

An ancient neolithic tomb that only sees the sun twice a year.

Possibly the oldest of Britain's ancient henges is also one of its most stark.

Thanks to both terrific preservation and historic vandalism this ancient site is known as the "Heart of Neolithic Orkney."

The largest stone circle in the world has ended up bringing up more questions than it has answered.

You can see three Irish counties from this Neolithic hillside fort, once the seat of the Kingdom of Ailech.

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.