Some Moscow residents once claimed the bizarre, contorted mass of metal on top of the building was used to manipulate minds.

Home of the future Emperors of Russia.

Dozens of padlock-trees along the Moscow River.

The tallest hotel in Europe.

Moscow's imposing monument to the Space Age.

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

A 250-year-old timepiece-automaton adorned with golden mechanical birds, which still sing to this day.

Former headquarters of the KGB.

Its front wall is striped with a menagerie of fantastic beasts and magnificent monsters.

This massive monument honors the first human in space.

This newly renovated Soviet-era outdoor exhibition center is bigger than the principality of Monaco.

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

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

The oldest housing complex in Riga is a mini timeline of architectural trends.

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

An abstract monument to a symphonic composer.

People have been living in the cave houses on this Italian hillside since the Neolithic era.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

The gloomy ruins that inspired Bram Stoker to bring Dracula to life.

A dead saint, a deadly poison, and a mysterious holy ooze.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

An underground city of salt.

Museum design and public transportation meet in this unique Russian train car.

Built to ward off Napoleon's army, this city-sized abandoned Russian fort is now perfect for urban exploration.