The Holzminden Tunnellers. Pupils may also choose the inspiring story of the Holzminden Tunnelers. The Holzminden prisoner-of-war camp was located in Germany and was a camp for captured British officers during World War 1. In July 1918 it saw the largest escape of World War One from a camp, where 29 officers escaped through a tunnel that had taken them 9 months to create. Ten managed to escape further capture and made it all the way back to Britain. The tunnel itself was concealed under a secret door made in the wall of a basement. Prisoners had to disguise themselves and dress up as orderlies in order to gain access to the basement block to dig. It remains one of the greatest escape stories.