The waterlogged tunnel threading its way beneath the hills of Lower Silesia amounts to a relic of one of Hitler’s most grandiose and futile projects. This subterranean passage, reached through a pair of black gates, was hacked out of the ground by prisoners and slave laborers. Their monumental task was to build bunkers and factories under the pine forests of what is today southern Poland, constructing a hiding place where a collapsing Third Reich might secrete its war industries and its treasures.
A damp concrete floor, dimly lit with a row of lights, stretched out before us. This led first to a small underground chamber with a swastika carved into the roof, alongside the national symbol of Ukraine – perhaps the work of Ukrainian prisoners. Then the tunnel sloped downwards, burrowing deeper into the ground. After about 900 yards, and several twists and turns, the passage broadened into a long and spacious chamber, at least 30ft high and 20ft wide – easily big enough for a train. Other chambers led off the main passageway, all similarly large.