This 11th-century castle sits so low you can't see it behind the surrounding buildings.

This stately council chamber hasn't changed since 1545.

The struggle of a small Dutch island against the sea.

This artificial ring island was built to hold cubic tons of polluted dirt.

Lombardy poplars planted to imitate the size and shape of the Cathedral of Notre-Dame de Reims.

The location of the world's first telescope demonstration.

This steel frame is a skeletal mirage of a lost 16th-century stone building.

Home to the world's oldest functioning orrery.

Rich with fauna and flora, nature-lovers can walk across the sea at this UNESCO World Heritage spot.

Live out your childhood construction fantasies in this one-of-a-kind gyrating hotel.

A seven-century-old jail tells a not-so-pleasant history of crime and punishment.

Strange secondhand shop showcasing taxidermy and oddies

The world's largest collection of ships in bottles.

A preserved building where the dead were once watched for signs of life.

An ingenious Dutch land art project uses grass ridges to cut airport noise pollution in half.

The elegant manor house where Kaiser Wilhelm II lived in exile after World War I.

This disused VLF radio station is no longer in service but the surrounding town still bears its name.

The ruins of a medieval castle that once belonged to one of the most powerful families in the Netherlands.

An enormous Polaroid picture adds an artistic flair to Rotterdam.

This colorfully-painted tunnel links two distinct parts of a historic neighborhood.

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

Crouch down, stretch tall, and be sure to flail your legs to pay homage to the Monty Python classic.

An art installation memorializing a tram stop, which became a tram stop.

A nearly 25-foot concrete sculpture of Sylvette, Picasso's muse.