South Korea's only sex-themed park.

Holy Grotto of Montserrat Monastery holds one of Europe's mysterious black Madonnas.

Transmission tower outfitted with large crossbars that dampen wind-induced oscillations.

"World machine" built by an untrained Austrian farmer.

Artifacts and memories from the Vietnam war, located in a place that experienced it first hand.

A gallery of underwater art that can be visited by man and fish alike.

This miniature Paris, built out of trash, is one man's two decade labor of love.

Rare and strange weather predictors, from mercury barometers to leech prognosticators.

A beautiful but toxic fountain of mercury.

A treasure trove of pathological, forensic, parasitological, and anatomical specimens.

A 30-acre garden inspired by the principles of modern physics.

All of Thailand's architectural landmarks, plus some made up ones, all viewable via two-seater bicycle.

Unusual outdoor collection of sculptures.

Virgil's many-mouthed gateway to the underworld.

A stunning cemetery famous for its extraordinarily delicate & lifelike mourning sculptures.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

A forest of phallic offerings found in a quiet corner of a hotel car park.

An eccentric garden of sculptures crafted in India decorate an Irish green space dedicated to Alan Turing.

Holding the current title of "biggest chair in the world," it stands with little fanfare in Lucena, Spain.

A battle between nature and architecture in the Cambodian jungle.

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