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

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

This unattributed sculpture in Amsterdam is hiding in plain sight.

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

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

A beautifully eclectic mix of architectural styles.

The history and future of cannabis.

A floating cat sanctuary on an Amsterdam canal.

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.

Cat art as far as the eye can see.

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

Museum preserving torture methods from the past.

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

The world's only museum devoted to the wonders of fluorescence.

Remote, beautiful, and stigmatized, Las Hurdes is Spain's version of Appalachia.

An ancient tomb that still stands in Portugal.

The medieval town's star-shaped walls are geometrically dazzling, though not entirely impenetrable.

An old wool-washing house filled with Fluxus contemporary art.

A chunk of the "true cross" is held in this small Portuguese church where modern day exorcisms are said to be common place.

An early Portuguese serial killer's head is alarmingly well preserved in a jar at the University of Lisbon.

This star-shaped military outpost is now simply trying to protect itself from neglect.

A majestic hotel for dreamers rises from the center of a fairytale wood.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”