The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

The world's largest collection of witchcraft regalia.

Notorious artist squat renovated into legal studios.

The world's only museum devoted to the wonders of fluorescence.

A snapshot of the city's fascinating voodoo culture.

A psychedelic labyrinth on the San Francisco bay.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

A church of bones, decorated with 40,000 human skeletons.

The sound of swaying stalks in this stunning grove has been named a governmentally recognized sound.

Medicinal spa created with the discharge from a geothermal energy plant.

World's largest collection of serial killer artwork and other macabre exhibits.

An exquisite tunnel of cascading flowers.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

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

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

Outsider Art Community.