Project Riese

In 1944 the construction sites in the Owl Mountains were allocated 28,000 tonnes of steel and cement – as much as the Third Reich set aside each year for air-raid shelters for its entire civilian population. Riese (German for "giant") was the code name of Nazi Germany's largest mining and construction project, carried out in 1943–1945 beneath Książ Castle and in several massifs of the Owl Mountains. It is not one site with one ticket but a group of separate underground complexes, some of which can now be visited with a guide.

An unfinished mystery

The project began in autumn 1943, when Allied air raids drove the Germans to look for safe locations in the Sudetes. Książ Castle and its surroundings were most likely being prepared as one of Hitler's headquarters, but the purpose of the tunnels dug into the mountains has never been proven – shelters, armaments factories and depots have all been suggested. The plans included tunnels, halls, a road network and a narrow-gauge railway. The work was never finished, and many entrances were blown up before the Red Army arrived. Estimates based on German documents suggest that about half of the corridors have still not been found.

Remembering the prisoners

The tunnels were dug by inmates of the Arbeitslager Riese camps, part of the Gross-Rosen concentration camp system – mostly Jews, among them people from the Łódź ghetto liquidated in 1944, brought here via Auschwitz-Birkenau. There were well over ten thousand of them at the very least, and German documents mention almost 30,000; the names of nearly 7,000 have been identified. Hunger, exhaustion, dangerous underground work and the brutality of the guards led to very high mortality. The tunnels are therefore also a place of remembrance, not just a military curiosity.

What you can visit

• Osówka near Głuszyca – 1,700 m of tunnels and large surface structures known as the "casino" (680 m²) and the "power station" (900 m²); choose the multimedia historical route, with an extreme route by torchlight as an add-on.
• Włodarz in Jugowice – the largest Riese site open to the public, with 3,200 m of corridors laid out in a grid; the route covers two levels, an underground cinema and a boat crossing through flooded passages.
• Rzeczka (Walim Adits) – three parallel adits with halls, about 500 m of tunnels; above ground stood a telephone exchange larger than Wrocław's.
• Książ Castle underground – a half-kilometre route through tunnels dug some 50 m below the castle, ending at the rubble of a buried lift shaft.

The other complexes – Soboń, Sokolec (Gontowa) and Jugowice-Jawornik – are largely collapsed or blown up and are not open to visitors. Do not enter unmarked workings.

Tripto tip

Each route is booked and paid for separately with its operator – check current hours and prices on the websites of Osówka, Włodarz, the Walim Adits and Książ Castle. At Włodarz the temperature is about 7°C with 95% humidity and the floor can be muddy, so bring a warm jacket and sturdy shoes you don't mind getting dirty. Allow 1–2 hours per site; if you want to see two or three complexes, set aside a whole day – you will drive between them on mountain roads.