The opulent home that inspired Tintin's Marlinspike Hall and the adventures within.

Designed to mark the geographical center of France.

One of the greatest maze designer’s greatest mazes.

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

A little known pile of scraps and plaques mark the grave of a downed RAF bomber.

Buddha and Jesus tower over this French mountainside headquarters of the Aumism religious cult.

The ruins stand as a somber reminder of France’s worst civil catastrophe of the 20th century.

This mosque was based on Sub-Saharan Islamic architecture and created for the Senegalese Tirailleurs.

These quaint French houses dangle precariously over a precipice.

This seaside sanctuary was once one of the most important religious sites for women in ancient Greece.

A gorgeous stone viaduct crosses over a bucolic valley.

The ruins of a 13th-century monastery that long served as a place of refuge from wars and raids.

Too much gossip or just missing curfew could land you in here for a couple of days.

Bohemian paradise covered in majestic forests.

The largest manmade caves in Europe now function as a motorbike club's headquarters.

Folklore says this medieval fortress was plopped atop a portal to hell to trap the demons below.

A church of bones, decorated with 40,000 human skeletons.

An enormous and lavish Gothic church in Czechia.

An ancient pagan site swirling with legends in the foothills of Franconian Switzerland.

Behold, a collection dedicated to Germany's favorite vegetable.

A Cold War secret surveillance tower used to spy on radio communications.

Each year, Germany's "City of Dragons" slays the world's largest walking robot.

This riverside restaurant has been serving customers since 1146.

These 18th century gardens tell a rocky story of the son of Odysseus.