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

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

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

More than 700 species live within this murky marvel of a swamp on California's coast.

From the sky, a kaleidoscope of color brightens the grey landscape of the San Francisco Bay.

The world’s first stop-motion film was created on the racetrack outside this building.

Rodin's famous depiction of Dante's 'Inferno', amidst a sculpture garden of many of his other works.

The site of murders and Satanic cult gatherings.

This naturally heated mountainous creek has created a group of neon blue pools of potentially deadly boiling water.

This rare example of a "tidefall" is a spectacular drop from the cliffs down onto the beach.

In this century-old literary safehouse, print is alive and well.

Everyone remembers Laurie Strode from Halloween, but this is the house where most of the blood was shed.

This abandoned Navy base was transformed into an off-grid alternative living community for thousands of people.

Finale of "William Tell Overture" can be heard as drivers pass over grooves in the road.

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

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

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

Carved by a waterfall in a hard-to-reach rock formation, this heart-shaped rock has inspired romantics for decades.

Tiki luxury on Nob Hill.

A look into the Church of Scientology's deeply unfavorable view of psychiatry.

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.

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

The ghostly remains of an accidental sea.

A hand-built folk art installation covered with messages of God's love.