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

Pivotal home of Nobel Prize winner Pablo Neruda.

Street artists transformed this abandoned industrial neighborhood into one of Europe's largest graffiti exhibitions.

A man has revenged his true love's betrayal through tears and stone genitalia.

This homeless brass fox tugs at your heartstrings from the foot of a Stockholm bridge.

A golden egg-shaped sauna in the Arctic tundra.

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

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

An ancient Viking runestone hidden in plain view in Stockholm's old town.

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

The world's largest model of our planetary system.

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

Stockholm's deepest subway station is also a stunning ecological wonder.

A hidden bathhouse in one of Stockholm's oldest and busiest neighborhoods is open to anyone who can find it.

The library's graceful rotunda is like a bibliophile's temple.

A rare surviving Victorian greenhouse designed specifically to house giant water lilies.

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

Sweden's first nuclear reactor, R1, can be visited 25 meters underground.

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

A stunning Catholic cathedral built by a curve-loving communist in Brazil’s newly created capital.

A huge boat-shaped hotel with a blood red pool and other oddities.

The haunting peak of an old church is all that remains of a drowned Brazilian city.

Part of one of the largest flooded cavities on the planet, and littered with prehistoric animal bones.

You feel like you're in a forest, but you're actually walking amidst the branches and trunks of a single giant tree.