One of the greatest maze designer’s greatest mazes.

This Parisian café sticks almost exclusively to an ethos of reuse.

The largest medical and anatomical collection in France lies hidden from the public.

Egyptian Revival movie palace abandoned for decades and restored in 2013.

France's national museum of scientific and industrial instruments.

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

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

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

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.

The oldest stone house in Paris was built by its most famous alchemist.

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

An iconic photograph from the Spanish Civil War saved this shrapnel-scarred historic house from destruction.

Continental Europe's only museum devoted to salt and pepper shakers features more than 20,000 designs.

Barça football fans might see the insignia hidden in a church window as a divine sign.

A tiny church remembers the Polish cavalrymen who charged their way into a Napoleonic victory.

Just like in Hollywood, Madrid has also a forgotten walk of fame.

A once grand hotel now sits eerily abandoned in the Catalan countryside outside Barcelona.

A curious memento mori hangs in the magnificent Cathedral of Segovia.

Whimsical sculptures and caves chiseled by nature over the millennia.

A delightful museum devoted to the history of books.

The gaunt visage of this angular Christ giant is enough to put the fear of God into all who see it.

The most elaborate of 12 medieval arched doorways to the old city of Burgos.

This species of wild goat stars in witchy legends and frolics among the park's eerie rock formations.