Devious political maneuvering and four ancient, working telescopes are central to the world's second-oldest observatory.

A lecture hall sink once used by Einstein and other noted physicists is now regarded as a strange science relic.

A former plague hospital turned medical museum.

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

One of the Leiden's oldest pubs is also the birthplace of the Heineken star.

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

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

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

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

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

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

A 200-year-old bar with a cheeky name claims to have served Edgar Allan Poe his final drink.

A curious collection dedicated to human and animal anatomy and pathology.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

Colorful and chaotic stacked hotel in North Holland.

A Dutch clog company in the town of Zaandam loves the wooden shoes so much it made a museum for them.

A public urinal so pretty, it was declared a national monument.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

This impressive collection of rare books on ancient mysticism inspired author Dan Brown.