A water reservoir disguised as a castle stands atop a hill in a park in Stockholm city.

A tiny metropolis resides inside this student housing complex.

A bridge that has seen many reiterations over its lifetime.

Not many houses move across borders, this one did it twice.

A tribute to smugglers and the Butter Wars.

This building once stood at the center of a butter war.

A former customs station on the border of Germany and the Netherlands.

A reconstructed World War I-era communications array that was once hidden in plain sight.

This residence straddles a border between Belgium and the Netherlands.

A maze of crosses marks the jumbled divide between the Netherlands and Belgium.

Only a few walls remain of the last church the Pilgrims used before they sailed to North America.

A massive stone fox oversees a Rotterdam elementary school crosswalk.

Banished from town, this local jester concocted a clever return.

A replica of a 17th-century map of the stars stands in the courtyard of a Belgian university.

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

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

A small statue commemorates a centuries-old event that still hangs over the people of Leuven.

Belgium’s famous peeing statue has worn many hats (and coats, and pants), which are on display at this small museum.

A set of seven houses, each built in a style that represents a European country.

This statue standing near Sweden's southernmost point was based on the grandmother of a modern movie star.

The highest point in Belgium is a staircase to nowhere.

Walk or bike along a narrow strip of Belgium sandwiched by German territory.

Where royalty waits in the height of luxury.

The former home of a mad diplomat is said to still be marked in bloody, arcane scrawls.