This funky former tobacco factory is one of the most striking examples of Madrid's cultural diversity.

A battle between nature and architecture in the Cambodian jungle.

Breathtaking and huge 430 year old maps of Italy.

A wall of chewing gum moonlights as collective art.

Caligula's colossal pleasure ships, discovered by Mussolini only to be lost in flames.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

An alchemist's "magic door" stands in the middle of a Roman park.

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

This off-beat, quirky communism-themed bar isn't afraid to poke fun at its history.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

A 19th century artistocrat's mansion, turned into a library, hidden in a modern library.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

Museum dedicated to the terror regimes of Hungary.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

The past, present, and future of Russia's signature alcohol is remembered in the world's only museum dedicated to the starchy spirit.

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

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

Former estate of Lenin, now home to his death mask.

Moscow's imposing monument to the Space Age.

Museum celebrating the achievements of the Soviet space program.

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