The only visible piece of San Francisco's most famous shipwreck.

An art supply shop holds the secrets of this quiet neighborhood's raucous Barbary Coast past.

A free, public museum dedicated to the fascinating science of sight.

The miraculous hydrant that saved the Mission District in 1906.

This 19th-century church is now a popular roller rink.

This private residence was the template for one of the most beloved television homes of all time.

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.

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

San Francisco's newly reopened hands-on science museum.

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

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

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

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

A psychedelic labyrinth on the San Francisco bay.

A huge musical instrument played by the ocean.

Furniture tries to escape an abandoned building in San Francisco.

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

America's oldest Italian restaurant is a San Francisco institution.

This New England drive-in was built to straddle the border between two states.

A beautiful maze marks where three countries meet.

If you visit Santa's village, you can get your passport stamped to show you crossed into the Arctic Circle.

A natural arch carved by a river gave its name to the so-called "Cave of Forgotten Dreams."

This magical-looking island is notorious for the misfortunes suffered by its owners.

The "Black Arch" guards the entrance to the picturesque Glens of Antrim.