foo-fighters or roadside attractions

During the last years of the war, Nazi scientists were working on a secretive underground construction programme in the catacombs of mines in the Lower Silesian region, code named Project Riese—Giant.

Although this massive project was presumably undertaken to house displaced administrative divisions along the Western front and as a logistical extension of Nazi-Germany’s deadly real and substantial rocketry programme, no one is entirely sure what was happening in these mine-shafts. Some believe, gleaned from various descriptions and accounts of forced-labourers, that a Wunderwaffe was being developed there. Die Glocke, the Bell, as the device was dubbed because of its shape, seemed to be a very mutable armament, the subject of much popular conjecture—and fearfully capable of anything or feasibly nothing at all.
Supposedly the housing was a containment field for a mysterious substance known as Xerum 525, speculated to be anything ranging from red mercury to anti-matter—and once activated, the device may have been an experimental fusion bomb, an anti-gravity propulsion engine, a TARDIS, or a sort of magic, quantum cauldron for looking into the future. “Foo-fighter” was the term that Allied airmen used for unidentified flying objects and other strange aerial phenomena. If die Glocke did exist, its ultimate fate is too unknown, some say it was an escape pod, some theorizing that it remains in South America and others believing that it’s mothballed in Area 51, with the occasional cameo-appearance, like in the 1965 space acorn incident in Kecksburg, Pennsylvania.