Touching this little fossil embedded in the wall of a grand mosque-cathedral may make your wishes come true.

This 2,000-year-old stone maze is one of the oldest in the country, but its purpose is still a mystery.

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

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

A prehistoric geological oddity tucked behind Stockholm's natural history museum.

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

A collection of trees from various corners of the world call Stockholm University home.

The world's largest model of our planetary system.

The 19th-century home of Count and Countess von Hallwyl is now a museum.

What looks like a birch tree smushed between two pieces of glass often confounds commuters.

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

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

Six beautiful wooden giants are hidden around Copenhagen.

Vortex-shaped aquarium hosts Europe's largest school of piranhas and other ocean creatures.

A 19th-century subterranean reservoir repurposed as a contemporary art cave.

Visitors are treated to a stained glass kaleidoscope interior inside this work of art.

Danish tourist destination well known for open stalls where vendors sell marijuana on the street.

Opulence and fantasy collide in this royal chair which is supposedly made with unicorn horns.

A little-known cafe in an old copper bridge tower with 360-degree views of the harbor.

A novel collection of medical curiosities housed in an 18th-century surgeon training academy.

This bridge's unique architecture honors nautical heritage and encourages self-awareness.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

The only surviving piece of Copenhagen's 16th-century defensive wall.

A collection of noses tucked inside an art museum reveals how times have changed.