This extremely narrow tenement boasts a maximum occupancy of just two.

The mystery of the Putim Ossuary involves a tricorn hat.

The prison where Hitler wrote "Mein Kampf," and 278 Nazis were later executed for war crimes.

Bring out your dead (saints that have been festooned and bejeweled, so that we can parade them around the town)!

The fairy tale castle of the "fairy-tale king."

The remnants of a fictional Viking village film set now serve as an educational and historical hotspot.

An abandoned football stadium with a tragic past.

These 18th-century paintings of Warsaw were used to reconstruct the city after World War II.

The site of one of the largest prison escapes of World War II.

Inside this Krakow church, an explosion of psychedelic color.

Deep in a Polish forest, this collection of Iron Age megaliths still holds onto many of its ancient secrets.

This fairytale medieval church in Poland originally spent centuries in Norway.

One of the world's largest collections of medieval religious art.

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

This imposing 20th-century castle was abandoned before it was ever completed.

A collection of old neon signs from all over Poland line a secluded courtyard.

A peculiar family mausoleum built by a German nobleman captivated by the occult.

A memorial to the beloved brown bear that served in the Polish army during World War II.

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

A fairytale Gothic castle steeped in Nazi treasure conspiracy theories.

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

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

An underground city of salt.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.