San Francisco's urban bison herd has persisted in the face of extinction, development, and disease.

A 300-ship graveyard, with a few still visible at low tide.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

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

Its buzzing collection honors vibrator history.

Get lost in this haunting fairytale art walk through a man-made eucalyptus grove.

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

There is no trying to fall in love with this Star Wars fountain, you just do or do not.

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

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

A psychedelic labyrinth on the San Francisco bay.

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

A huge musical instrument played by the ocean.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

A picture-perfect town, perfect for blowing up.

After a water tower painting was accused of being an ad, a simple fix was made that gave the city a motto.

A suspended garden, now gone, once hung in the middle of this abandoned church.

The largest earthwork effigy in the world.

A slab of sandstone covered with mysterious 1,000-year-old rock carvings from a vanished North American culture.

One of the last few period-correct, hand-operated canal locks in the country.

This moving cemetery sphere is a slowly rolling stone.

A single handprint, which, according to Ohio State University legend, cannot be scrubbed off.

The childhood home of one of Ohio's favorite sons, pilot and war hero Eddie Rickenbacker.

Thousands of artifacts relating to human sexuality, including the world's largest sex bike.