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

Olfactory delights in San Francisco's Botanical Gardens.

Its buzzing collection honors vibrator history.

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

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

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

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

A natural dome made of volcanic glass in Inyo National Forest.

Towering basalt columns, a creation of fire and ice.

The interior of the Overlook Hotel in "The Shining" was based on this Yosemite original.

A glimpse into the lives of the the Miwok and Paiute people in Yosemite National Park.

Under the right circumstances, this waterfall in Yosemite briefly turns a luminescent fiery orange.

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

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.

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

A huge musical instrument played by the ocean.

A psychedelic labyrinth on the San Francisco bay.