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

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

Rare recess caves fill this unbelievably beautiful Ohio park.

This sign marks the entrance to a tiny proto-state within the small country of Moldova.

Learn about Iceland's hidden folk at this school dedicated to the study of elves.

Climb right into the heart of this colorful Iceland volcano.

One of the most remarkable caves in all of Iceland was created by a once raging river of lava.

A modern Nordic Pompeii on the Icelandic island of Heimaey.

This fantastical waterfall is hidden in a cave located in a cracked cliff.

The oldest hall in Iceland was written of in the Sagas and features a centuries-old escape tunnel.

The unique waterfall in Iceland's south features a backdrop of geometric black lava columns.

Staves, storm-calling, and of course, necropants.