From the sky, a kaleidoscope of color brightens the grey landscape of the San Francisco Bay.

This mysterious, medieval cathedral remains unbuilt but fiercely protected.

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.

This cemetery served as the only official burial grounds in Cambridge for nearly 200 years.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

A flooded Mexican cave that hides a river beneath the water.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

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

This delicate museum is devoted to the art and industry that once supported Cape Cod's oldest town.

The world's largest piece of copyrighted artwork.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

Many of the murals covering this sleepy Florida town hide some sort of intentional error.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Funded by John D. Rockefeller, this is one of the earliest, and most beautiful, shopping arcades in America.

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.

Nevada's largest cactus collection stands outside a candy mogul's small factory.

A miniature view of the park, caught in time.

A small section of Boise, Idaho maintains the unique culture and traditions of the Basque people.

Radioactivity still cause for concern at this urban explorer's paradise.

Faceless white figures loom over the city from the rooftop.

The only remaining place where you can play this century-old game for cash.

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

Once adorning a New York skyscraper, these reclaimed ruins now haunt an Indiana park.