Sweden's largest optical telescope sits on a rooftop in Stockholm.

"Only the dead get off at Kymlinge."

Eat a Nobel banquet from any year in the basement of Stockholm's City Hall.

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.

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

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

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

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

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

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.

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

A microbiologist-chef is slinging noodles with hyperlocal Nordic ingredients.

The Vatican's secret porn-festooned bathroom was painted in erotic murals by one of the greatest artists of the Renaissance.

Over 50 exquisite hand-painted Renaissance maps decorate a Medici storage room.

The largest and most famous wax anatomical collection anywhere in the world.

Hidden beneath a beautiful overlook you’ll find the history of the city depicted in comic strip format next to a pay toilet.

One of the smallest bookstores on the planet.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

Ring the bell to enter a bar that looks equal parts museum and old curiosity shop.

The world's oldest bookshop still in operation.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

One of Europe's largest supercomputers is housed inside of a disused chapel.