The longest continuous lava tube in the continental U.S. offers 2.5 miles of dark explorations for the adventurous.

A museum dedicated to the history and exploration of both popular music and science fiction.

Stroll through a wonderland of stupendous moss-covered trees.

A 100-year-old purveyor of curiosities, curios, and kitsch featuring mummies, shrunken heads, and a Fiji Mermaid.

A giant Troll lurks under one of Seattle's oldest bridges.

San Francisco Bay's ghost town.

Big gun installations, built over a massive cemetery, now abandoned & hidden in trees.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

Canyon walls shrouded in ferns.

A shop full of natural curiosities, carnivorous plants, and costumed taxidermied mice.

One of the most scenic stretches of road in America winds between some of the country's oldest trees.

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.

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

An underground mansion with fruit-bearing trees and grapes growing beneath the surface of central California.

Olfactory delights in San Francisco's Botanical Gardens.

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

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

A hand-built folk art installation covered with messages of God's love.

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

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

The rocks in this arid basin leave trails of movement behind them.

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

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