Giant granite rocks standing end-to-end like a train of circus elephants.

400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

Less a museum than a bizarre fantasy world created by artists and engineers.

The Magic House provides a beautiful and creative environment for curious youngsters to get their knowledge on.

A historic house in St. Louis was plagued by a series of suicides committed by family members involved in a successful brewery.

What was once a presidential estate is now an exotic menagerie and home to the Budweiser Clydesdales.

This is not your typical jungle gym.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

This massive redwood tree has a hole in the base big enough to drive through.

The fossilized remains of ancient California redwoods.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

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

The key to turning shifting dunes into the green oasis of Golden Gate Park.

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

Once the fastest ship from San Francisco to Tahiti, the Galilee now lays in pieces in three different cities.

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

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

An elaborate gift from Claus Spreckels is now a piece of San Francisco history.

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

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

This shop specializes in oddities and Victorian-inspired wonders.

A nondescript building that's been functioning as a speakeasy for nearly a century and a half.

San Francisco's oldest surviving monument and meeting place for 1906 survivors.