For over 100 years the most important physicists in the world have autographed this university wall.

A relic of the old jail still stands in its original location.

This century-old street sign is a forgotten remnant of the old city.

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

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

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

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

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

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

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

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

Once housed in the towers of this Gothic church, this 17th century clock still ticks today.

A market built atop boats is one of the few floating holiday markets in Europe.

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

Graffiti covers the walls of a room where university students through the centuries have waited nervously to defend their theses.

An ancient Egyptian temple sits within a modern European museum.

This historic Dutch newspaper building is covered with media-themed details—and one unrelated oddity.

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

This large sand dune in the Netherlands is home to wind-whipped trees with "floating" roots.

The works of poetry's biggest names grace the walls of the city of Leiden, all carefully painted by hand.

The tallest waterfall in the Netherlands is a lovely, stepped feature that is only 50 feet tall.

Tucked away in the Leiden city hall are a group of works by famed artist MC Escher.

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

Go inside a revolutionary, cage-less zoo where 70 species of monkeys roam free alongside their human visitors.