San Francisco Bay's ghost town.

A cozy bookstore is tucked within an old gold mine shaft beneath the cafe and ice cream shop.

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

A massive hydrovolcanic explosion left a half-mile wide crater in Death Valley.

Rusty pieces of metal jutting out of a breakwater are all that's visible of the 12,500-ton ocean liner that capsized just off the beach.

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

The blinking light atop the iconic landmark has been sending secret messages for decades.

A beloved carnival gets a modern makeover in Los Angeles.

This 19th-century church is now a popular roller rink.

Peek inside this sandy mailbox and you'll spot kids' letters to Santa.

This stately structure has been abandoned for half a century.

This store is dedicated to unique found footage and the strangeness of pre-internet pop-culture.

A hospital closed seemingly in the middle of operations, leaving behind fodder for horror films and ghost hunters.

This hidden amusement park is a magical escape for kids and kids-at-heart.

Prone to disastrous fires, the city of San Francisco has the Guardian, a fireboat gifted by residents, to watch over them from the bay.

A strange house built only at night, with rumored mystic inspiration.

Venue for strange sideshow displays and musical acts.

One man's homage to the sun continues to grow like a glass fractal.

America's most famous piece of self-built architecture.

The ghostly remains of an accidental sea.

A trash dump made beautiful by nature's power.

Every year, over 25,000 monarchs overwinter in Pacific Grove.

A huge musical instrument played by the ocean.

The rusting remains of the largest assembled WWII fleet on the West Coast.