The bizarre visions of H.R. Giger, tucked away in a Swiss medieval city.

Abandoned railway line circling the city of Paris.

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

This charming cobbled backstreet is the most Instagramable street in Paris, much to the residents' annoyance.

A magical, macabre wax museum, beloved by locals, uses real artifacts to depict an assassination from the French Revolution.

The video game-themed street art first popped up in the French city.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

A marble Lucifer hides behind the pulpit of this Gothic cathedral.

This abandoned Belgian fortress is purposefully being left to nature.

The smallest museum in Basel, Switzerland, is a two-foot-by-two-foot window in the door of a 600-year-old house.