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

The Habsburgs' royal collections of art and wonders.

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

This elegant arc of a waterfall marks a religious turning point.

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

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

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

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

For patriotic Russians, this memorial honoring the Soviet soldiers who died liberating Berlin in 1945 is the most sacred location outside of Russia.

This watchtower once presided over the Berlin Wall.

The walls of Germany's Parliament still show the scars of the Red Army takeover in World War II.

This World War II bunker now survives as a documentation of the Nazi regime and war crimes.

A fascinating insight into daily life in the Eastern Bloc.

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

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

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

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

Dr. Strangelove-esque tours reveal the inside a bunker once reserved for Stalin himself.

Several plaster noses are hidden in plain sight around London's Soho neighborhood.

Museum preserving torture methods from the past.

This nostalgic Russian museum is full of USSR cultural artifacts from the 1970s and 80s.

A dormant lightning machine equal to all the power in Russia.

An early-20th-century "dacha" village of quaint cottages curiously located in a modern part of Moscow.

The oldest museum in Russia is home to a fascinating collection of nearly two million anthropological artifacts and anatomical curiosities.