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

Museum devoted to the artificial language of Esperanto.

Handsomely crafted representations of our round planet.

In the middle of a Vienna square, Roman ruins dating back some 2,000 years are on display.

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

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

The palace window through which Protestant nobles flung two Catholic regents, thus sparking the Thirty Years' War.

Countless grotesque faces stare out from this eerie Prague art wall.

Two stunning 17th-century libraries and a cabinet of curiosities.

This automated sculpture of two men peeing will spell out text messages with their micturition.

This walkway is so narrow it needs its own light to stop pedestrian traffic jams.

A Jenga-style cylindrical tower of books that appears to go on forever.

The oldest arboretum on the Dalmatian coast doubles as the gardens of Kings Landing in "Game of Thrones."

Where the lovelorn find a home for their sentimental keepsakes.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

The holes in this wall provide a glimpse into Jewish life in Budapest, both past and present.

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

A statue in Budapest's Liberty Square honors the former U.S. president's efforts to end the Cold War.

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.

An authentic replica of an Asian temple and garden hidden amongst the natural beauty of Hawai'i.

This museum of Hawaiian and Polynesian culture is the legacy of the last descendant of the Kamehameha Dynasty.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

This steep cable railway has been hoisting passengers in the heart of Québec City for over a century.