Thanks to a quirk of elevation this gift shop produces magic doughnuts that are found nowhere else on Earth.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

The highest bridge in America was built for an almost unnervingly small amount of money.

A breathtaking array of ancient Pueblo structures and artifacts counterintuitively preserved by neglect.

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

A man-made island in scenic San Francisco Bay.

The miraculous hydrant that saved the Mission District in 1906.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

A winding path built in secret on the edge of the continent.

The only theatre in the world constructed specifically for sound movement.

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

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

A miniature view of the park, caught in time.

An elaborate gift from Claus Spreckels is now a piece of San Francisco history.

The grand, column-fronted, sculpture-adorned home of the ambitious digital library.

San Franciscans leave gifts and messages for the magical beings that live behind the tiny, mysterious door installed on a tree in Golden Gate Park.

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

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

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

A hidden subterranean installation offers a view of the sky.

A pair of slides and a tree-lined stair corridor have been an urban oasis for nearly 40 years.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

A tiny theater hidden in an alley plays a constant stream of short silent films for anyone willing to peer through the peephole.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.