Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

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.

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

Op-art architecture designed for happiness.

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

Macabre museum devoted to historical Viennese murders.

A heavily politicized roundabout discussing the state of a heavily politicized country.

A tribute to the first human in space.

This museum in the tower of the oldest church in Gdańsk, is home to centuries-old time-keeping devices and the world's first pulsar clock.

The last king of Poland was interred in this church nearly 200 years after his death.

This colorful and quirky set of pegasus sculptures celebrate the works of poet Zbigniew Herbert.

An artificial date palm stands as a memorial to Warsaw's Jewish community.

The manor house where the Polish composer spent childhood summer holidays is now a museum and concert hall.

An impressive monument to Poland's independence.

The first, and perhaps only, monument dedicated to Wikipedia.

A cluster of headless, armless sculptures looms within a popular Polish park.

In the summer, the area around this sculpture transforms into a vibrant concert venue.

Hundreds of notes give thanks to the patron saint of lost causes.

Relive a Polish uprising via an enormous, century-old cyclorama.

This towering statue of Jesus provided internet to the surrounding area.

This enormous 32-foot painting depicts Poland's greatest medieval battle in glorious detail.

In the center of Wrocław's old meat market stands a somber tribute to the city's livestock.

The coffin-shaped church was once home to monks who slept in coffins.