Stockholm's narrowest alley is barely over two feet wide.

The single richest source of elemental discoveries in the world.

It's always game time at Stockholm's only museum devoted solely to video games.

No one knows who's responsible for decorating this tunnel with stuffed animals, but the people love it enough to protest their removal.

Dine on food tied to Viking history and legend at this subterranean Stockholm spot.

Now a hotel, this former bank was the site of a robbery that spawned a psychological phenomenon.

Sweden's "good old days" painstakingly re-created in a model village.

This Stockholm light tower can be controlled by anyone with a smartphone.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

An illuminated manuscript comprising the life's work of a lone monk, inexplicably decorated with a portrait of Satan himself.

This cafe offers a curated collection of treats and tipples made by monks and nuns.

A temple to modernity, tucked away amid Barcelona's more well known museums.

A beautiful but toxic fountain of mercury.

This subterranean studio is filled with fascinating kinetic art.

A unique collection of gilded age mechanical pianos.

This basement museum explores the art and artistry of fascism.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

The history and future of cannabis.

Cat art as far as the eye can see.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

A curious collection dedicated to human and animal anatomy and pathology.

Museum preserving torture methods from the past.

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