One of the larger complexes built by prisoners under the German supervision in 1943 - 1945, within the “Riese” program (The Giant). The most interesting in terms of variety of mining and underground construction and on the surface works. The hotel was never completed. Up to date, no documents were found concerning its destination. There are only some information preserved about the structure of the Riese complex in the Owl Mountains. In them we find the testimony of Albert Speer, the Minister of Armaments of the Third Reich, informing that the Germans wanted to build an underground city here for twenty thousand of armed soldiers with the Hitler's residence in the Ksiaż castle. Today the visitors can explore the 1500 metres of underground corridors and halls in various phases of drilling and construction of underground galleries, exhibitions and expositions, and part of the building exterior.