"Only the devil could play golf here."

The fossilized remains of ancient California redwoods.

One of the most unusual geological features, recognizable from a dozen hit movies.

An optical illusion found amid a logged redwood forest.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

The giant pair of sexy legs sticking out the window of this costume store have become its main draw.

A collection of memorabilia from the Beat era in the back of a San Francisco bookstore.

This private residence was the template for one of the most beloved television homes of all time.

The largest drain hole in the world.

One of the last free public hot springs is decorated with hippie art.

Golden Gate Park's historic collection of plants.

The lowest point in North America is home to an undrinkable pool surrounded by fields of geometric salt flats.

This massive redwood tree has a hole in the base big enough to drive through.

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

Eons old volcanic activity created one of the most stunning rock formations in the United States.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

Canyon walls shrouded in ferns.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

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

Quite simply the largest tree in the world (by volume).

An underground mansion with fruit-bearing trees and grapes growing beneath the surface of central California.

The ghostly remains of an accidental sea.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

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