Funhouse of found art and participatory sculpture.

This old residential building was once the largest flour mill in the world.

The only arched bridge made of stone on the entire Mississippi River.

When flour explodes, it's not a pretty sight.

One of the northernmost occurrences of western juniper can be found in the sand dunes of Washington's Palouse.

The sail of the first nuclear sub to circumnavigate the world.

Oregon's unexpected high desert, displaying layers of time in a colorful show.

One of two observatories in the U.S. that routinely detect gravitational waves.

Whitewashed mosque contains the world's largest carpet.

This enormous sports car themed amusement park is home to the world’s fastest roller coaster.

This massive piece of artwork weighs more than 250 tons, and was designed as a tribute to the first president of the United Arab Emirates.

A sinkhole and now a swimming hole, too, full of dazzling turquoise water.

This spectacular mosque houses the second-largest chandelier in the world.

This bazaar is one of the oldest in the Arabian world.

The world's largest frame offers spectacular views of the city's past and present.

Billed as the "largest natural flower garden in the world" this Middle Eastern show field has little competition at 45 million flowers.

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

A library built during San Francisco's pioneer times is a student's retreat, bibliophile's sanctuary, and chess player's delight.

A still functioning vaudeville carousel that has operated for over a century boasts a colorful menagerie and past.

Beneath the southern end of the Golden Gate Bridge is the “Gibraltar of the West Coast,” a fort built to protect the San Francisco Bay from naval attack.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

One of the oldest producers of hand-folded fortune cookies still uses its original secret recipe.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

A rare tour of a commercial jet assembly plant, held inside one of the largest buildings in the world.