Overlooking the Rhine Valley, Frankenstein Castle dates back to the Middle Ages and is tied to both legend and history. It was once home to Johann Konrad Dippel, an alchemist rumored to experiment with reanimation, inspiring elements of Mary Shelley’s Frankenstein. Visitors report ghostly apparitions, unexplained shadows, and cold drafts in the ruined halls. Paranormal investigators highlight the chapel and towers as active hotspots. Each Halloween, the castle hosts one of Europe’s largest haunted festivals.