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

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.

Barely visible foundations remain where Stow Lake’s “observatory” once welcomed visitors.

A favorite haunt of dinosaur loving children and hallucinogen loving hippies alike.

Over 315,000 preserved amphibians and reptiles in jars.

The stones that traveled from Spain to eventually become a holy place for San Francisco's nature worshippers.

A famous alternative culture epicenter and where Joplin serenaded young hippies.

The giant pair of sexy legs sticking out the window of this costume store have become its main draw.

The remains of a 12th-century chapter house in Golden Gate Park.

An overlooked and unassuming engineering marvel.

This turn of the century masterpiece has a mysterious goaty interloper.

Golden Gate Park's historic collection of plants.

Adolph Sutro's little-known, geographically inaccurate, deprecated monument.

An artsy hidden staircase leads to breathtaking views of San Francisco.

An essential stop before plundering, BYO Cutlass.

The miraculous hydrant that saved the Mission District in 1906.

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

These subterranean storage areas hold emergency water reserves.

Since 1973, this block has been home to the most concentrated collection of murals in San Francisco.

Forgotten and then destroyed by fire, this was once one of the largest saltwater swimming pools in the world.

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

A 140-year-old castle with underground caves hidden in San Francisco.

The peaceful gravesite of a rugged wild west gunman echoes the touching story of his last days.

A rough granite monument marks the spot where Europeans first caught sight of the San Francisco Bay.