A small museum filled with over 1,000 clocks, and one particular clock calibrated to run until the year 9999.

A plaque hidden in the law faculty at Leiden University honors the first scientist to make liquid helium.

A late-medieval Dutch castle with trick fountains in its whimsical water gardens.

This public library and its impressive collection of academic books have not changed since the 17th century.

The world's first interactive human body museum also serves as a chair for a giant orange man.

People have been placing babies on these lilies for photoshoots since the Victorian era.

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

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

A retail shop has preserved the 17th-century food cellar from the old building it now occupies.

Lumps of significant stone from around the world surround a flaming monument for peace.

One of the great math minds of the 17th century is underfoot in this 900 year old Dutch church.

A massive explosion that leveled hundreds of buildings in the city of Leiden is remembered by a waterside plaque.

Now a museum, this building was once a 14th-century monastery and the place where the founder of the Dutch nation lived and was assassinated.

An unassuming rod in the Netherlands was once the old standard unit of length for the entire Dutch empire.

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

An ancient Egyptian temple sits within a modern European museum.

Made of 41,900 pieces of mosaic, it took two years to piece together this giant egg.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

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

One of the oldest masonic temples in the Netherlands, built in 1757.

A trio of red, white, and blue stones embedded in the streets of Leiden are markers of medieval territory and law.

This neighborhood of futuristic ball houses looks like an alien settlement in a science fiction film.

Remarkably preserved body discovered in a peat bog.

Science meets wall art to highlight the beauty of famous mathematical equations.