Elusive Polish Treasure Train

According to this story in The New Yorker, there is a culture of treasure hunting in southwest Poland. With good reason: they keep finding abandoned tunnels.  

The Nazi Underground: Is treasure hidden beneath the mountains of Poland?

by Jake Halpern

The New Yorker, May 9, 2016

"Starting in 1943, the Nazis began building a series of underground bunkers beneath the Góry Sowie, or Owl Mountains, in Lower Silesia. All told, there were seven facilities...Historians believe that the Nazis intended to connect these facilities with tunnels; and some treasure hunters...insist that the tunnels were completed and then sealed off by the German military in the last days of the war. The problem with the tunnels, from the treasure hunters' point of view, is that they present a seemingly endless number of possibilities. Each new passageway, even if it is empty or a dead end, leads to a spot where another passageway may start."