A once-magnificent collegiate church is falling into ruin.

Drink among marionettes at this pub inside a historic puppet theater.

A marble Lucifer hides behind the pulpit of this Gothic cathedral.

Hiding the longest subterranean river known in the world.

The oldest cemetery in Belgium.

A fascinating and enormous collection of natural history exhibits stained by a dark colonial legacy.

One of Belgium's oldest hospitals saw patients from the 13th to 20th centuries before becoming a museum.

A beautifully eclectic mix of architectural styles.

Cat art as far as the eye can see.

The history and future of cannabis.

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

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

The former headquarters of history's oldest megacorporation.

The facade of this bank has changed little over the centuries, including its unique welcome sign.

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

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

A floating cat sanctuary on an Amsterdam canal.

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

The vast, legendary catacombs hold secrets much stranger than stacked bones.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

France's most famous cemetery, with some of its most curious tombs.

This cheese shop also houses a museum devoted to Dutch dairy.

This basement museum explores the art and artistry of fascism.