The largest drain hole in the world.

A unique market that brings together various goods and cultures.

An abandoned, unfinished mansion on grounds strewn with lava rocks.

A speck of nature and art in one of San Francisco’s most notorious neighborhoods.

Tiki luxury on Nob Hill.

Rising out of miles of farmland, these buttes are sometimes called the world's smallest mountain range.

Furniture tries to escape an abandoned building in San Francisco.

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

An optical illusion found amid a logged redwood forest.

Concrete strongholds stand guard over the Golden Gate.

An ominous concrete cube cuts a dystopian silhouette atop this California mountain.

Here, visitors can swing with the waves of the Pacific Ocean.

This concrete ship has had four careers - World War I tanker, floating amusement park, fishing pier, and artificial reef.

This quirky roadside attraction dives into the many theories surrounding North America's most infamous hairy cryptid.

A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

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

At this 1940s-era neighborhood favorite, you can still drink a cherry phosphate.

This bakery sits on the site of the Black Panther Party's first headquarters.

An abandoned convention space that has been left to the homeless and the radical.

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

The world's first permanently occupied mountain-top observatory continues to report on the stars.

A glimpse into the lives of the the Miwok and Paiute people in Yosemite National Park.

The largest permanent Monopoly board makes one of the longest games even bigger.

A giant chess set, minus the psychedelic drug trip.