This ancient market is often referred to as the oldest shopping mall in the world.

One of the most important yet well-hidden museums dedicated to the history of medicine.

The only remaining arch of the oldest stone bridge in Rome stands in the middle of the Tiber.

A hospital where antique dolls are given new life.

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

A unique hotel for the artistic soul.

Museum dedicated to the terror regimes of Hungary.

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.

Late at night, the bust of the "Dracula" actor was snuck onto the facade of this Budapest castle.

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

A statue in Budapest's Liberty Square honors the former U.S. president's efforts to end the Cold War.

Uh, pardon me, ma'am, but I couldn't help noticing that there's a Columbo statue in the middle of Budapest.

The industrial architecture honors the laborers who brought the Exposition Universelle of 1900 to life.

An off-the-beaten-path boutique stuffed with an eclectic collection of upcycled goods.

Museum on French naval history, with magnificent figureheads, a historic diving suit, and a boat used by Napoleon.

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

A unrivaled and rather horrifying collection of wax dermatological models.

This Parisian fountain is a little bit fantasy and a little bit nightclub.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

Paris' fabled purveyor of exotic taxidermy and natural history curios.

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

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

A museum of magic with a Sadist past.

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