Every weekend, the parking lot of this Buddhist temple turns into a Thai street-food paradise.

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

The "Greatest Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

A forgotten "city of water" underneath the famous Trevi district.

2300-year-old Roman road connecting the empire.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

Smooth basaltic rocks tell a tale of ancient glacial waterfalls.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

A natural dome made of volcanic glass in Inyo National Forest.

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

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

A free library to stumble across, one of many placed worldwide if you know where to look.

Three vintage horses survived a 1976 inferno and found a home on a sister carousel.

This traditional garden in the San Fernando Valley doubled for Star Fleet Academy, and is irrigated entirely by wastewater.

A spiritual retreat in the heart of Los Angeles offers stunning gardens and a labyrinth to lose yourself in.

This serene oasis in an affluent Los Angeles neighborhood holds some of Gandhi's ashes and got Elvis into Eastern Philosophy.

A castle that was built stone by stone by an eccentric journalist.

Rainbow-hued local gem in Venice.

Hidden in the hills of Hollywood, this secluded Oz-themed garden is dotted with dozens of thrones.

This weird abode has inspired everything from the "House On Haunted Hil" to a robot hunter's pad.

America's most famous piece of self-built architecture.

One man's homage to the sun continues to grow like a glass fractal.

Non-profit time travel mart sells goods you would need for a trip through the fourth dimension.