Visiting this café is like visiting the Austrian grandma you wish you had.

Inside the corridors of this flea market, visitors are sure to find some obscure and odd treasures.

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

Apartment complexes built into huge repurposed natural gas tanks.

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

Vienna's underworld of tunnels and subterranean rivers made an iconic appearance in a 1949 Orson Welles film.

A silly medieval mural preserved on the side of a Viennese house.

Op-art architecture designed for happiness.

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

The topiary maze at the Habsburg hunting lodge.

The final resting place for the remains of 143 Habsburg royalty.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

The beautiful baroque library of the Hapsburg empire.

This centuries-old gothic monster has been converted into a sprawling, glossy bookstore.

'The Letters of Utrecht' lays out a ribbon of poetry one letter at a time, with no final verse in sight.

Super-heavy Nazi architectural experiment.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

A fascinating insight into daily life in the Eastern Bloc.

Where once there was a train station bathroom, there is now this German burger joint.

Art and a pun, all in one.

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

A slice of central Asia in the middle of Berlin.

When this 18th-century observatory's meridian was moved, it set Sweden's time back by 0.04 seconds.

Stockholm's narrowest alley is barely over two feet wide.