An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

This Soviet statue is based on a piece of propaganda that's been elevated to national myth.

In Kazakhstan, a colorful cathedral with many lives once survived the most powerful earthquake in the region.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

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

A centuries old castle atop a dormant volcano houses museums devoted to both women and witches.

One of the largest barracks of the Austro-Hungarian monarchy's military is now an abandoned ruin.

"Medieval" castle built in the mid-20th century by one family.

This shining multicolored metro station deep under Naples is said to be the most beautiful in Europe.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

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

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

Elaborate tile work in this railway station tells the story of Portugal.

This quiet, unassuming spot in Budapest was the birthplace of the bloody 1956 Hungarian Revolution.

This easily overlooked memorial immortalizes the scars from the 1956 Hungarian Revolution.

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

The geographical center of Budapest is marked with a 10-foot-tall stylized zero.

A Hungarian optometrist's charming collection of Asian art and curiosities.

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.

A random tree outside a Budapest hotel has become a DIY shrine to the late singer.

Legions of Roman soldiers bathed in this ancient spa complex under a Budapest transit station.