An amusement park on the grounds of an unused nuclear power plant, with a swing ride inside the cooling tower.

Underground attraction offering tours of the foundational ruins of a church nave that collapsed in 1674.

A historic observatory now an astronomy museum beautifully situated at the moat of the Middle Age city centre.

The world's largest bicycle shelter can hold more than 12,500 two-wheelers.

The world's first fish doorbell monitors this water passageway.

This enormous storm barrier is one of the largest moving structures on Earth, with each arm taller than the Washington Monument.

Old ships and machinery fill a historic harbor in the city that's home to Europe's largest port.

These slanted cubic abodes are a creative if odd solution to a zoning pickle.

This hotel was once home to a steamliner company and became the final rest stop for Europeans heading to the New World.

A miniature city, once ruled by the Queen of the Netherlands.

Volkswagen's dedicated museum dives into the complex history of one of the world's best known cars.

The real life town from the Pied Piper of Hamelin has a mechanical puppet show that retells the famous story many times a day.

Model Trains and Much More in Hamburg.

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

Hamburgers are intensely proud of their tunnel beneath the river.

Preserved "bog person" that is over 2,000 years old.

Iron Age "bog person" preserved for over 2,300 years.

This Danish rock field is actually a sprawling ancient cemetery holding the bodies of 700 Vikings.

A natural wonder in south Denmark.

Four alabaster giants contemplate the tides on the shore of Denmark.

The original home of the Lego has a huge amusement park dedicated to the iconic plastic toy.

Mounds, rune stones, and a 1,000-year-old church, left behind by Denmark's first two kings.

This unique architectural wonder is home to luxury apartments.

A perfectly circular stronghold constructed in the 10th century is now a nucleus of Viking culture housing a museum, village, and reenactment of an epic Viking battle.