The house of physicists Paul Ehrenfest was also a temporary dwelling and study for his good friend Albert Einstein.

From afar it looks like someone's hat blew into the water, but closer inspection reveals a giant floating sculpture.

The cutest way to stay safe in traffic.

Every winter, this former planetarium is transformed into a massive, brightly-lit Christmas ornament.

A nuclear reactor created for Eisenhower's "Atoms for Peace" campaign is now used for research at a Dutch university.

The remains of a medieval wall discovered in the basement of a jewelry store.

Albert Einstein would often sit in this chair during visits to the observatory to discuss science with Willem de Sitter.

This plaque marks the former home of one of the first women physicians in the Netherlands.

This bell tower is the only one of its kind in the Netherlands and was a symbol of prestige.

For over 100 years the most important physicists in the world have autographed this university wall.

This giant radio telescope would be a rusting ruin if it hadn't become such a beloved relic.

Most complete collection of Gymnosperms in the world.

A large measuring stick marks the lowest point of a country that is partially under sea level.

While most bridges allow roads to pass over water, this one allows water to pass over a road.

It's forbidden to dig within this ancient Roman fort hidden beneath a playground.

This public toilet built in the famous Amsterdam School architectural style is a Dutch national monument.

These lights mark the area of Rotterdam that was bombed and burned in 1940.

Portraits of musicians line Oude Binnenweg, the jazziest street in the city.

Preserving the research tools, unexpected inventions, and odd collections of generations of college professors.

Once housed in the towers of this Gothic church, this 17th century clock still ticks today.

A set of beech hedges planted in the 19th century forms a tunnel that takes on a different appearance in every season.

This early 19th-century graveyard is the final resting place of Vincent van Gogh's mother.

Once the world's biggest telescope, it was later used as a coat hanger by a famous Dutch astronomer.

This collection of 20th-century toys is filled with a lifelong personal toy collection brought from the U.S. to Amsterdam.