This half-finished "city of toys" was almost Italy's own Las Vegas.

This centuries-old Italian chapel hangs midway down a sheer cliffside.

Five candy-colored villages on the Italian Riviera.

Romans built the world's tallest artificial waterfall in 271 BC.

Dug as a secret royal escape route, the tunnel became a wartime bomb shelter and dumping ground for vintage cars.

This shining multicolored metro station deep under Naples is said to be the most beautiful in Europe.

Hidden in an Italian forest is a completely homemade amusement park that has taken a lifetime to create.

Sitting on an Italian hilltop is this surreal fortress built by the mad inventor of electrohomeopathy.

According to the local folklore, the myriad colors of this lake are the result of a lovelorn wizard's blunder.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

The Sighignola summit on the Swiss border offers views so breathtaking it's been named one of the most beautiful places in Italy.

The history of German architecture is explored across this fairy-scale mini-city.

A massive explosion that leveled hundreds of buildings in the city of Leiden is remembered by a waterside plaque.

Preserving the research tools, unexpected inventions, and odd collections of generations of college professors.

The mass grave of the 27 victims of the "Vampire of Hanover."

Goethe's "Faust" was inspired by these rock formations known as the "Devil's Pulpit" and "Witches' Altar."

A strange rock formation with numerous legends trying to explain it.

Bursting forth from a historic German neighborhood, these day-glo palaces are now a bright fixture in the town.

This small town in the Netherlands has no roads but instead, miles of canals and over 100 bridges.

This former hydraulic laboratory is now a woodland dotted with old engineering models.

Hundreds of large Russian nesting dolls decorate this square, and the largest is a functioning hotel.

Nestled in the woods lies this land art project: a hybrid between park, maze and natural monument.

Repurposed space and ultra-modern construction collide to create this geometric wooden spectacle.

This single-track road rewards brave drivers with stunning Scottish scenery.