A war-torn Olympic relic is being overtaken by graffiti and nature.

These warring psychedelic crags commemorate an unsuccessful military operation.

This cluster of little wooden huts once ground local farmers’ wheat into flour during the days of the Austro-Hungarian Empire.

There's a mini version of Iguazu Falls hidden in the Balkans, and it's got a rope swing.

Bridge that died in war and was resurected.

Ride a dragon train into a world of dwarves.

Vienna's underworld of tunnels and subterranean rivers made an iconic appearance in a 1949 Orson Welles film.

The largest ice cave in the world is thought to be the entrance to hell according to Austrian legend.

Each year melting snow turns these Austrian hiking trails into scuba zones.

These cascading falls resonate throughout the Bulgarian forest.

This tiny Bulgarian town offers a stunning location in the mountains and a storied history.

An industrial site turned into Hungary's most cherished natural wonder.

The massive white mound and accompanying water terraces are a striking geological oddity.

The abandoned "Red Star Train Graveyard" is the final rusting place for precious artifacts of train history.

A curious cave church carved into the face of a cliff.

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

This region of Slovakia boasts some of the most plentiful opal mines in the world.

The 700-year-old fortress was the site of Count Orlok's castle in "Nosferatu."

A hidden stream deep in the mountains creates one of the largest tufa waterfalls in Serbia.

A Roman monument to their own civil engineering prowess.

The ridged layers that make up this river canyon represent Earth's geological history.

The interior of this Serbian royal family's mausoleum is covered with exquisite mosaics.

The bizarre rocks of Đavolja Varoš are the result of natural erosion.

Structure built from the skulls of vanquished foes.