This grubby wall is said to be one of the Earth's esoteric energy centers.

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

Krakow's own version of the Hollywood Walk of Fame.

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

A statue commemorating a Polish dog who took his role as man's best friend very seriously.

A collection of modern and vintage pinball machines housed in the cellar of a 15th-century building.

This man-made mound monument was built out of soil from all across the Polish empire.

This sprawling concrete suburb of Kraków was designed by the Soviet Union as the model proletarian city.

Dubbed "Wistom" by locals, this abandoned factory is an urban explorer's dream.

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

Poland's oldest salt mine has nearly everything one needs to live underground forever.

An underground city of salt.

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

Art and a pun, all in one.

Berliners converted a bombed-out, disused lot into a community-run urban farm with its own cafe and bar.

Where once there was a train station bathroom, there is now this German burger joint.

This abandoned hospital has a long history, having housed both German and Soviet soldiers in the course of its life.

This grandiose staircase was part of the revival of a medieval Spanish architectural style combining Christian and Islamic influences.

An underground city beneath Krakow's postwar socialist utopia.

Mysterious Spanish catacombs of unknown origins.

A film center envisioned to rival Cannes ended up as a haunted place after at least 168 people were killed during the rushed construction.

An early masterpiece of Le Corbusier, a famed Modernist architect, hiding in plain sight.

When German-Iraqi relations broke down, this embassy was vacated post haste.

A state-of-the-art medical facility from the Imperial era is now a derelict ruin.