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

One of Amsterdam's narrowest houses is located right across the canal from its widest.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

Amsterdam's narrowest house facade is a monument to 17th-century tax evasion.

In the middle of a Vienna square, Roman ruins dating back some 2,000 years are on display.

The housing complex served as an anti-fascist fortress during the Austrian Civil War.

On a winding Vienna side street, one museum has turned their windows into a monument to history’s peace-minded heroes.

A rooftop restaurant hides in plain sight atop Vienna's Palace of Justice.

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

An exquisite Baroque church in Vienna's old town.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.

The townhouse where the "Blood Countess" Elizabeth Báthory started her murderous career.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

Legends surround an ancient tree trunk riddled with nails for good luck.

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

Op-art architecture designed for happiness.

Dine amidst exotic plants at this former royal greenhouse.

Located right outside of Vienna, visitors can take in expansive views of an ethereal forest.

This former insane asylum now holds a pathological anatomy museum.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

This subterranean necropolis holds three floors of antler-dug grave caves.

This prison on the Maltese island of Gozo is almost 500 years old, and they have the graffiti to prove it.

A Beaux-Arts triumph set to become Ford's innovation campus

An abstract monument to a symphonic composer.