The struggle of a small Dutch island against the sea.

The place where Czar Peter I of Russia resided in 1697 during his Grand Embassy.

Birthplace of the "Cat in the Cradle" and a cluster of iconic, original windmills that let the Dutch tame the seas.

The Bloemen Route, or “Flower Route”, stretches 25 miles through prime Dutch tulip country as a result of “tulip mania,” the world’s first economic bubble.

This small town in the Netherlands has no roads but instead, miles of canals and over 100 bridges.

An 18th-century Spanish watchtower made entirely of seashell and concrete.

Orthodox church partially financed by Tsar Nicolas II.

Arguably the best example of an authentic Dutch windmill in the United States, rivaling its counterparts in the Netherlands.

This historic hotel invented the chocolate brownie.

A gothic church spire sits atop this skyscraper, the tallest church in the world.

The former home of a mad diplomat is said to still be marked in bloody, arcane scrawls.

A unique collection of gilded age mechanical pianos.

The spectacular history of spectacles on display.

A floating cat sanctuary on an Amsterdam canal.

Cat art as far as the eye can see.

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

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

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

A subterranean shelter remains intact under a busy Paris railway station.

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the century.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

This off-beat, quirky communism-themed bar isn't afraid to poke fun at its history.

This hidden art nouveau gem was designed by an architect in search of a national style.