Hamburgers are intensely proud of their tunnel beneath the river.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

Tiny memorials honor individual victims of the Holocaust.

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

Home to 10,000 medical specimens including the remains of Rudolf Virchow's extensive collection of pathological specimens.

Metro station with a claim to rock n' roll fame.

Macabre museum devoted to historical Viennese murders.

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

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

Collection dedicated to funeral rites, equipment, and mourning rituals of the Viennese.

This cubist Vienna church building looks like some sort of alien stonehenge.

Op-art architecture designed for happiness.

Among the ostentatious rococo ornamentation of this church, an image of death cuts the life-thread.

Rare documents, old instruments, and gruesome specimens showcase the history of military medicine.

This Russian museum stresses the importance of keeping clean and even holds one of Pavlov's dogs.

Moscow's most popular cemetery includes the graves of numerous cosmonauts.

Thirteen sculptures in central Moscow graphically depicting vices of the modern world.

It took over half a century but a Russian monument to a famous and tragic space pup finally stands in Moscow.

Moscow's other, lesser known kremlin is a fairytale-like cultural complex modeled after Old Russia.

One of the world's tallest statues is also one of its most hated.

The tallest hotel in Europe.

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

Twisted buildings adorn the banks of the Rhine river.

The beautiful, ornate weather station is the most popular geocache in Salzburg.