An ethereal glowing blue ocean cave in Croatia.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

These warring psychedelic crags commemorate an unsuccessful military operation.

Bridge that died in war and was resurected.

This surreal memorial/cemetery is a necropolis of crumbling stonework and puzzle-shaped headstones.

The sad remains of a monument to martial arts legend and movie star Bruce Lee—in the middle of Balkans.

Oriental bazaar in the heart of Sarajevo.

The place where World War I began.

A number of craters left by fatal mortar strikes have been filled with red resin to remember those lost during the Siege of Sarajevo.

This museum preserves the hand-dug tunnel that kept Sarajevo afloat during the Serbian siege.

Poland's oldest surviving university building holds a wealth of historic science instruments including some used by Copernicus.

Polish luminaries and masterful folk art find sanctuary in this unique cemetery.

The unsettling remnants of a torn down movie set lies nearby the ruined location of the actual Płaszów Labor Camp.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

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

Real bones which are said to have belonged to a Polish dragon.

The silly symbol for an underground protest group is now scattered around the city.

These mechanical goats first battled it out in the year 1551, all because of an overcooked deer.

After the famous composer died in Paris, his sister snuck his heart out of the country to honor his wish that it be buried in their native country.

The world’s narrowest house makes for an awkward, four-foot-wide living space.

Museum dedicated to "the man who moved the Earth."

A former steam-powered mill from the 1800s is now an industrial park with a giant steel dragon slide.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

Mountain where Jesus was first tempted by the Devil.