A small but immensely extravagant palace built by the "Night King."

A preserved Nazi labor camp now has a Holocaust museum on site and memorials to the thousands that died while imprisoned at the camp.

A popular shrine where the Blessed Virgin allegedly appeared in 1830, displaying a holy armchair and two incorruptible remains of Lady Saints.

The subterranean "lake" below the Paris opera house inspired the Phantom of the Opera's lair.

A subterranean shelter remains intact under a busy Paris railway station.

This museum houses an imposing skeleton army comprised of creatures great and small.

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the century.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

Notorious artist squat renovated into legal studios.

France's most famous cemetery, with some of its most curious tombs.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

This is not only one of the oldest collections in Europe, but also possibly the most beautiful.

This 170-year-old Swiss guesthouse built into the side of a mountain is best accessed by a cable car.

In one of the world's smallest countries, a royal's personal winery is open to the public.

The scars of World War II are preserved on its walls.

A fearsome dragon clings to a corner of Munich's city hall.

The footprint of a frustrated devil in Munich's Cathedral.

Among the ostentatious rococo ornamentation of this church, an image of death cuts the life-thread.

Golden cobblestones remember a time when this small alley was used to avoid having to give a Nazi salute.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

The patron saint of spinsters grasps a container of dried blood.

A stairway to heaven, or to nowhere at all.