Książ Castle's hidden Nazi tunnels reveal a brutal WWII project

Książ Castle in Lower Silesia, Poland, holds a dark chapter from World War II. Known as Schloss Fürstenstein until 1945, the grand estate became a Nazi Hitler's project for Project Riese—a vast underground construction effort. Behind its Baroque and Renaissance walls lies a network of tunnels tied to forced labour and unanswered questions.

The castle's origins trace back to the Middle Ages, growing into Poland's third-largest castle through centuries of aristocratic ownership. Its opulent halls and sprawling grounds once symbolised Prussian nobility. But in 1944, the Nazis took control, repurposing it for a sinister goal.

Project Riese aimed to build seven massive underground complexes across Lower Silesia. Over 13,000 prisoners—many Jewish inmates from Auschwitz and Gross-Rosen—were forced to excavate the tunnels under deadly conditions. Historical records estimate around 5,000 died during construction.

Post-war investigations confirmed the project's true purpose: armaments production, not a secret Hitler's headquarters. No archival evidence, such as OKW orders or Hitler's directives, links the site to his command. Yet myths endure, including tales of a hidden Nazi gold train buried in the nearby Owl Mountains.

Today, nearly a mile of tunnels beneath Książ Castle is open to visitors. Exhibits document the brutal history of Project Riese, contrasting with the castle's regal past.

The tunnels stand as a stark reminder of wartime suffering, while the castle's lavish architecture tells a different story. Though no proof supports claims of buried treasure or Hitler's involvement, the site remains a focal point for historians and tourists. Its dual legacy—of grandeur and atrocity—continues to draw attention decades later.