The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

A Bicycle Path in the Sky.

A decommissioned Naval base now rents itself out for people who want to blow stuff up.

This abandoned motel doesn't welcome guests anymore, but decay and a creepy atmosphere still call it home.

A pier that used to act as a busy ferry dock is now a decaying favorite of local fisherman and urban artists.

Once the largest winery in the world, this castle-like building now sits abandoned on the San Pablo/San Francisco Bay shore.

Not truly a ship nor a building, the Navy's first and last "landship" is now abandoned due to clerical issues.

Elephant seals and sea lions have turned the abandoned buildings on this island into their endangered love shack.

Built by the inventor of the radio, this abandoned hotel has housed early radio employees, military men, and a dangerous cult.

The "Fun Spot of the Desert" is now a haunting ruin, and a reminder that putting a water park in a desert is a bad idea.

Hidden beneath a lake for decades, this brutalist mine has now emerged from beneath the receding waters.

A crumbling wizard is one of the final reminders of a roadside Middle Earth.

The graffiti-covered remnants of a former triangulation station are balanced precariously on this California peak.

Once a place of peaceful repose, this sanitarium now faces an uncertain future.

An abandoned 1920s-era stretch of cabins now overshadowed by the 66 Motel.

Once America’s most beautiful army base, this abandoned military fort on the coast of Monterey Bay has been left to the elements.

An abandoned boat that's been stranded mysteriously for decades.

A ghost town originally established and governed solely by Black Americans seeking a place of their own, free from discrimination.

This little gem of Spanish Colonial architecture has been abandoned since the 1950s.

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

The overgrown ruins of a once thriving World War I-era copper mine.

The abandoned train depot now doubles as a well-placed rest stop for those who take the road less traveled.

Before it was abandoned and left to rust alongside the road, this riverboat starred in a John Wayne movie.

Salt is slowly eating away this abandoned saltworks town in the desert.