Isenstein, Germany, was a small town on the Rhine River. A young man from the United States stopped in Isenstein while touring Europe. Here, he was abducted by Regin Fafnirsbruder, and taken into the past. Isenstein was a few small houses at this time. Trapped, the young man had no choice but to stay in medieval Isenstein.
In the Nibelungenlied, Isenstein was located in Iceland.