A floating cat sanctuary on an Amsterdam canal.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

The world's only museum devoted to the wonders of fluorescence.

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

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

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

Walk upon the mementos of the dead in this Parisian courtyard paved with medieval tombstones.

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

A counter-culture bookstore like no other hides in plain sight in the streets of Paris.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

A haunting collection of the vanished and disappearing natural world.

A museum of carnival attractions where you are invited to ride the rides.

Paris' linguistic guide to the international language of, yes, love.

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

This massive library holds what was once the largest book collection in the world.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

Abandoned railway line circling the city of Paris.

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

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Two thirds of this Montreal neon icon has survived to flash another day.

A massive Montreal stadium that has seen nothing but trouble since its inception.

Its columns were all carved from the same white oak tree.

Every year, the colorful murals of Montreal get a complete makeover.