A favorite Paris bar for U.S. expats, including Gershwin, Hemingway, and James Bond.

Famed for its pie, this eatery has a hidden tunnel that allowed Catholics to secretly walk to church during the Reformation.

A sanctuary for sickly, stray, or wounded donkeys.

This gigantic monument hidden in the woods was built to thank the Dutch for sheltering Belgian refugees during World War I.

This steel frame is a skeletal mirage of a lost 16th-century stone building.

The birthplace of most all of Europe's space missions is here on the Dutch coast.

A set of 27 bamboo tubes creates an eerie soundscape that changes with the wind.

Visit the ancient, mysterious Roman catacombs ... in the Netherlands.

Live out your childhood construction fantasies in this one-of-a-kind gyrating hotel.

Two gravestones clasp hands over the religious divide.

Crouch down, stretch tall, and be sure to flail your legs to pay homage to the Monty Python classic.

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

Crumbling ruins of the thermal baths that once attracted royals and aristocrats from throughout Europe.

Ham is serious business at the Prosciutto Museum-Serious, delicious business.

These delicate sand pyramids look like naturally occurring gothic spires.

This ancient Roman prison is decorated with an upside-down cross not as blasphemy but as saintly tribute.

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

2300-year-old Roman road connecting the empire.

Geothermal waterfalls in Tuscany.

Stalactites and stalagmites in a beautifully lit cave.

Renaissance villa and gardens complete with a tormented colossus.