A castle from the Holy Roman Empire that hosts traveling youth... in its stables.

This lurid German fountain plots the sad course of marriage from dating to death.

This beautiful 19th-century temple stands atop the ruins of its predecessor.

The scars of World War II are preserved on its walls.

One of the most easily accessible examples of the rare 1960s UFO houses.

The prototype for all Nazi concentration camps.

A subterranean display of public art and architecture.

At 929 pounds and 26 feet tall, this stainless steel fork can only be used by the likes of King Kong.

In Grand Rapids, Michigan, a marker honors the creation story of a proud fictional culture.

Along the Rhine, about a mile from the historic Munster, learn the heartrending story of two lovers torn asunder, cast into unknown layers of time and space.

An interactive exhibition space dedicated to the kinetic sculptures of Swiss artist Jean Tinguely.

An unassuming Swiss institution houses Europe's largest toy museum.

A church filled with the bones of hundreds of virgins martyrs—or so they say.

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

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

This large copper bolt represents the benchmark for measuring sea levels in most of Europe.

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

A poignant mural honors the heroic teenage non-conformists who took on the Nazis and paid the ultimate price.

In downtown Oslo, a menacing and terrifying relief clings to a church wall.

Thousands of miniature bronze sculptures have taken over this city square creating a unique art installation.

This floating sculpture of ice is a poignant reminder of nature's power.

Tens of thousands of tiny bottles stuffed with various items.

Home to three historic ships from the age of Vikings.

An elegant chandelier hangs over this ancient sewer chamber, now open for concerts and public tours.