Spiral labyrinth hidden in the hills above Oakland, CA.

Natural catch-basin rocks covered in thousands of drawings spanning many millennia.

Eat like pre-Columbian Native Americans in this New Mexico restaurant within the Indian Pueblo Cultural Center.

The official atomic museum of the United States explores the explosive and productive history of a much maligned energy source.

This is one really big nut.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

Elevated freight railway turned wildly successful urban park.

The second building of its name to occupy this location might be the finest flatiron building in San Francisco.

A nondescript building that's been functioning as a speakeasy for nearly a century and a half.

There is no trying to fall in love with this Star Wars fountain, you just do or do not.

Model Trains and Much More in Hamburg.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

What started as a tongue-in-cheek shrine is now a full-blown museum celebrating "The Hoff" and his longtime love affair with Berlin.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

When the rain falls, this drain system turns into a musical instrument.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

At the base of the Golden Gate Bridge, a small sign basically begs for a high-five.

This tea house was a hand-built gift from Boulder's sister city in Tajikstan.

A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

This concrete ship has had four careers - World War I tanker, floating amusement park, fishing pier, and artificial reef.