World's Most Mysterious Buildings
Pontino / Alamy
Mont Sainte-Odile, France
When ancient books began disappearing from this seventh-century monastery in France’s remote Vosges Mountains, speculation—even among the police—naturally turned to possible secret entrances. That line of thinking was vindicated when a bookcase swung open and exposed a forgotten medieval passageway with rope ladders leading to the roof and public areas. The thief turned out to be a local teacher who spied the hidden space on an old map and couldn’t resist investigating. Mystery solved—for the moment.
—Kelsi Maree Borland