The archaeologists discovered German artifacts from the World War II era in the buildings, adding to their belief that Nazis were behind the construction of the building. "Apparently, halfway through the Second World War, the Nazis had a secret project of building shelters for top leaders in the event of defeat -- inaccessible sites, in the middle of deserts, in the mountains, on a cliff or in the middle of the jungle like this," Daniel Schavelzon, from the University of Buenos Aires told Clarin.The researchers believe, however, that, the Nazis never ended up using the hideout.Argentina let in a number of Nazi fugitives following World War II, including Adolf Eichmann, who was captured by Israeli commandos in the South American country and brought back to the Jewish State where he was executed.