This unusual rock looks like a giant, otherworldly mushroom sprouting atop a cave.

The ruins of Scottish sea salt production.

This tiny little cave was said to have been a refuge for a saint with a glowing arm.

Islanders once used this dramatic, otherworldly landscape to hide their cattle from Viking raiders.

A church that bred legends, and served as an inspiration for the Da Vinci Code.

The ruins of this gorgeous clifftop castle look like something from a fantasy novel.

Ancient cliffs resembling a kilt on Scotland's second largest island emit an entrancing sound.

An ancient Scottish rock formation said to be the gravesite of a giant remains ensconced in legend and intrigue.

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

This huge concrete map of Scotland was built as a thank you gift from a Polish soldier.

The Bloemen Route, or “Flower Route”, stretches 25 miles through prime Dutch tulip country as a result of “tulip mania,” the world’s first economic bubble.

Tucked in the back of a flower shop, its collection details the fascinating history of the Netherlands's iconic symbol.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

This medieval tower is all that remains of the castle where Joan of Arc was held before being burned at the stake.

This enchanting mountain plateau celebrates spooky local folklore.

This small museum nestled inside a souvenir shop is dedicated to Sweden's most well-known toy.

This small museum in a 17th-century building honors three iconic Scottish writers.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

People in Poland have rallied to save this unnatural desert from being reclaimed by the forest.

On this Polish road, an optical illusion makes cars seem to roll uphill.

In the center of Wrocław's old meat market stands a somber tribute to the city's livestock.

This oddly beautiful water cistern is a techno-temple to the wet stuff and a multimedia masterpiece.