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

Cat art as far as the eye can see.

This bird-loving brewery is situated in an old municipal bathhouse, nestled beside a 300-year-old windmill.

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

A beautifully eclectic mix of architectural styles.

A collection of biblical memorabilia.

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

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

A floating cat sanctuary on an Amsterdam canal.

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

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

The attic of a four-century-old canal house hides a clandestine church.

The largest bell in the world has been swinging high above a Cologne cathedral for almost a century.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

A church filled with the bones of hundreds of virgins martyrs—or so they say.

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

This beautiful 19th-century temple stands atop the ruins of its predecessor.

This century-old cinema house has a marquee that has been hand painted by a single man for over 25 years.

Go surfing on this urban wave, "hacked" by local surfers.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

One of the most easily accessible examples of the rare 1960s UFO houses.

The footprint of a frustrated devil in Munich's Cathedral.

Golden cobblestones remember a time when this small alley was used to avoid having to give a Nazi salute.

The patron saint of spinsters grasps a container of dried blood.