This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

This museum in a Paris apartment gives a unique look at the iconic French singer's life.

This Parisian café sticks almost exclusively to an ethos of reuse.

Egyptian Revival movie palace abandoned for decades and restored in 2013.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

A haunting collection of the vanished and disappearing natural world.

Paris' linguistic guide to the international language of, yes, love.

This massive library holds what was once the largest book collection in the world.

No one knows how this Pacific Northwest spruce tree came to have so many trunks.

Remember that scene in the Matrix, when Neo is in the big white room with all the weapons flying by? Well, this is what it would look like if he had wanted trees instead of guns.

Hollowed out cedar log tubs set in an ancient towering forest.

An eccentric folk art landmark made out of discarded bottles by an inspired "grandma."

Julia Morgan's Moorish-Gothic labyrinth of fountains, trees, natural light and Oakland's notable dead.

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

Historic funicular railway, believed to be the shortest railroad in the world.

The last of its kind in the country.

Its buzzing collection honors vibrator history.

Resting place of Hollywood's immortals is also site of summer film screenings.

The only theatre in the world constructed specifically for sound movement.

The legendary building that needed ghostly approval before being built.

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

California's own medieval Italian castle, authentic down to the 300-year-old iron maiden in the dungeon.

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