Sweden's first electric elevator remains hidden within a fortress-like building.

This unique sculpture is often overlooked by pedestrians.

The Grand Lodge of Ireland is one of the oldest in the world, full of fantastical, elaborately themed rooms.

This enigmatic artifact is a rare depiction of an ancient Iberian noblewoman.

These three pillboxes still remain as a witness of the Spanish Civil War in a park of Madrid.

A lush indoor jungle fills this bustling Madrid transportation hub.

A marvel of technology a century ago, this disused power station now offers a lovely glimpse into the industrial design of the past.

This spa theme park lets its guests take a dip in pools of coffee, wine, or ramen broth.

These magnificent 240-year-old machines are considered distant ancestors of the computer.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

This off-limits room in the National Library of France is home to a system of pneumatic tubes, once used to bring books to readers.

A lone cannonball remains lodged in the walls of the Hotel de Sens as a sober reminder of a revolution.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

You'll find just about anything in this funky Tbilisi flea market.

Religious structure known for its sculpted details.

This snug medieval lane is one of the narrowest streets in the world.

The bust of Romania’s most notorious ruler, Vlad Dracula aka "Vlad the Impaler," keeps watch over the ruins of his medieval court.

An abandoned socialist utopia built in the late 19th century.

A curious carving hides on a marble column in the Mosque-Cathedral of Córdoba.

Of course Salvador Dalí lived in a castle...

This grand hydraulic installation has provided water for townspeople since the Middle Ages.

Buildings from the fictional planet of Tatooine still litter the Tunisian desert.

The largest salt lake in the Sahara is mysteriously alluring.

A gorgeous stone viaduct crosses over a bucolic valley.