This architecturally eclectic early-20th century mosque was built as a place of worship for the Islamic followers of a Jewish messiah.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

This is not only one of the oldest collections in Europe, but also possibly the most beautiful.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

A saintly relic hidden in a Prague church basement.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

A turn of the century building boasting some of the most beautiful art nouveau architecture in Prague.

A mocking tribute to the past and modern leadership of Prague.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

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

Tucked away near more famous landmarks lies a statue meant to symbolize the confluence and continuing development of human culture.

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

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

A vast Communist-era exhibition space in the Bulgarian capital.

A Bulgarian monument to Russia's role in World War II is constantly being painted in pop culture protest.

A striking symbol of the Bulgarian capital.

"Holy Wisdom" overlooks the city that became its namesake.

A pair of connected skyscrapers form this symbolic gateway.

A small memorial to a deadly night in Serbia that shook the world before it was swept under the rug.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

A misnamed well, with a deep dark past.