A Stockholm metro station is home to an escalator that is not only the longest in Sweden, but among the longest in the world.

This small museum nestled inside a souvenir shop is dedicated to Sweden's most well-known toy.

Outside a Viking museum sits a modern-day runestone made by a Swedish runemaster using traditional methods.

The single richest source of elemental discoveries in the world.

When this 18th-century observatory's meridian was moved, it set Sweden's time back by 0.04 seconds.

This grisly exhibit houses skeletons and weapons from a devastating 14th-century clash.

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

The discovery of an old wall led to the creation of this fascinating museum about the city in the Middle Ages.

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.

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

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

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

It houses the remains of a 17th-century version of the Titanic.

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

This charming, hidden guild museum holds some 700 years of crossbow history.

The Belgian royal family's private depot now stands abandoned and forgotten alongside the tracks.

Cozy basement bar sports an inventory of over 2,000 beers.

This cannonball embedded in the side of an Edinburgh house once served a surprisingly pedestrian purpose.

The 20th-century chapel’s intricate woodwork includes amazing details, most notably angels playing bagpipes.

A pair of stones embedded in an Edinburgh street memorialize one of the city's last public hangings.

Touching this 18th-century Scottish philosopher’s toe allegedly conjures good fortune.

The colorful stairs are made with marble from the world's major quarries.

These steps offer a breathtaking view of one of Europe's most besieged fortresses.