Tucked in the back of this amazing antique store is an important piece of medical history.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

A repurposed railway tunnel with otherworldly acoustic characteristics.

This huge pile of volcanic boulders hides a stunning network of secret grottoes.

Hundreds of stone stairs and a winding medieval bridge connect this haunting Spanish island to the mainland.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

This huge abandoned fortress hidden inside a mountain holds a world of subterranean secrets.

BDSM, 1930s Style.

Skeletons, medical artifacts, and other obscure and precious treasures all displayed in a wooden pharmacist's cabinet.

Behind the pink curtain, Au Bonheur du Jour, an art gallery of erotic archives.

An enchanting work of outsider art, full of whimsical sculptures and carvings.

This abandoned Belgian fortress is purposefully being left to nature.

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

The sign at the garden gate reads: "These Plants Can Kill."

Hundreds of secret cabinets built into the walls of legendary poisoner's private work room.

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

The largest underground church in Europe.

The bizarre home and sculpture garden of an eccentric artist.

Artist and musician Will Menter creates musical sculptures.

Limestone grottoes turns everyday objects into stone.

Beautiful carved tunnels.

Do these monsters look familiar? The gargoyles on this church are all from pop culture.

One woman's decades-long obsession with the "La Fée Verte."

The somewhat misnamed 'Garden of Shells' lovingly built from found objects.