Famously misunderstood wonder of the ancient world

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

Eighty million natural history specimens call this gargantuan museum home.

Macabre astrological automaton clock dating to the late 1400s.

Holy Hindu shrine in an enormous, monkey-filled limestone cavern.

A castle from the Holy Roman Empire that hosts traveling youth... in its stables.

This historic toy museum brings a little whimsy to a city not usually remembered for such things.

This lurid German fountain plots the sad course of marriage from dating to death.

It has an American Dream Car exhibit, Europe's largest Formula One collection, and many, many mannequins.

The world's first and only three-segment bascule bridge folds up into the shape of a capital "N" to let boat traffic through.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

Real bones which are said to have belonged to a Polish dragon.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

Taking the subway here means doing so over a bridge located in the middle of an estuary.

Dress up like a miner and take a slide into the disco-lit depths of this once foundational salt mine.

Austria's ultra-modern art museum looks like Cthulhu's giant alien heart.

Celebrated example of Ottoman architecture that also served as a site for brutal massacres.

The architect of this fanciful complex called it an "oasis for humanity and nature in a sea of rational houses."

Hitler's bleak vision of relaxation still stands as a mostly abandoned 10,000-room resort complex.

Iceland's largest lagoon is home to stunning multi-colored icebergs.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

Climb this overlooked gem's spiral staircase and you'll be rewarded with spectacular views of Glasgow.

Displaced highlanders would take shelter from the wet Scottish climate under the large walled bridge at Glasgow Central Station.

An icon of the Battle of Britain is frozen in flight in a grand Victorian museum.