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

Europe's official "zero-level," the equator of elevation.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

The former headquarters of history's oldest megacorporation.

Amsterdam's former hotspot for public executions and dissections.

Amsterdam's narrowest house facade is a monument to 17th-century tax evasion.

This contentious squat has stood through fire, violence, and government intervention as a hotbed of leftist protest.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

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

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

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

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

Site of the first radio and telephone broadcasting companies in Copenhagen.

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

Copenhagen's celebrated theme park and gardens.

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

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

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

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

A fake town founded by Western movie stars is now becoming a hip desert community.

A collection of the best toys ever made, The National Toy Hall of Fame is filled with kids, fun, and for some reason, a bird preserve.

Comprehensive gaming collection of over 30,000 electronic games and consoles.