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

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

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

The remains of an idyllic small town built for the film 'Big Fish' still stand around a rundown main street.

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

Part modern art project, part traditional chapel, this see-through church is only substantial from the right angle.

These azure waters were thought to lead to the Mayan Underworld.

One man has carved a number of natural New Mexico caves into psychedelic sandstone temples.

Fall down the rabbit hole into a surreal journey of human consciousness "from ass to soul."

According to one local tradition, the entrance to the Voodoo underworld can be found in New Orleans through seven gates scattered throughout the city's French Quarter.

A hard-to-reach oasis in a desolate corner of Death Valley National Park.

World's largest cave was only discovered in 1991, and now offers tours to the public.

Florida castle built with aluminum printing plates.

The humble home where the famous beat author lived briefly and wrote one of his most famous works.

This home is decked out like a psychedelic explosion of colors and bowling balls.

Welcome to old Florida, where a 1940s mermaid show is still enchanting visitors.

Meet manatees face-to-face at this zoo for native species.

This fairytale-inspired cottage was created by a university literature professor.

Working compound meant to allow visitors to reclaim the values and traditions of the past.

A giant 400-acre preserve in North Florida for displaced wolves.

A humid oasis combines recreation with exploration in a unique underwater cavern.

This relatively recently abandoned brewery is a tragic reminder of the continuing effects of Hurricane Katrina.

Storyville was New Orleans' historic red light district and hotbed of jazz music, sometimes referred to simply as "The District."

A 200-year-old building in the French Quarter that was to be Napoleon's home in the New World.