The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

Commonly referred to as the most photographed Victorian home in the United States.

Secret Manor, a house full of legends, the least of which is the haunting of long-deceased ladies of pleasure.

Experience a quartz crystal sound bath inside a storied, all-wood sound-chamber.

Where the polar bear watches over everything, and every drink is a double.

An art collective teaching the more fiery, metal-y art forms.

A Roman-inspired temple once controlled half of San Francisco's waters.

A restored 1920s cascade stairway provides one of the best views of Oakland's Lake Merritt.

Julia Morgan's Moorish-Gothic labyrinth of fountains, trees, natural light and Oakland's notable dead.

The haunting ruins of Jack London's dream house.

An abandoned car and strange wooden debris are among the scattered remains of the old sand and gravel quarry.

Breathtakingly blue walls shimmer inside the "Glacier Behind the Town."

Pompeii's less famous neighbor is still revealing her secrets.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

A swing to dangle you off the very edge.

Monasteries on rock pillars, once accessible only by frayed ropes.

The longest hedge maze in the world.

A fiery crater has been burning in the Karakum Desert since 1971.

An underwater city for the dead.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

This strange seaside tower got its name from a wealthy eccentric who would hide coins among its stones.

Ruins of a German Castle on top of a towering stone pillar.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.