A miniature train-ride through Slovenia's largest cave system.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Trick water gardens from 1619 featuring a 200 piece mechanical theater powered by water.

The famous winding walk at Chartres is surrounded in mystery and myth.

An ancient ossuary in Rouen.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

Baroque celebration of the end of the Great Plague of Vienna.

The Habsburgs' royal collections of art and wonders.

The former private quarters and office of Dr. Sigmund Freud now hosts a museum housing the works of the founding father of psychoanalysis.

Tiny memorials honor individual victims of the Holocaust.

A brush maker used his factory to protect blind Jews from the Gestapo.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The most visited, and possibly most controversial, museum in Germany.

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

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

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

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

Monument to a suicide protesting the Soviet invasion.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Macabre astrological automaton clock dating to the late 1400s.

A church of bones, decorated with 40,000 human skeletons.

An enormous and lavish Gothic church in Czechia.