Is Frankenstein Castle haunted?
Germany Reported haunting level 3 of 5

What actually happened
The alchemist Johann Conrad Dippel was born here in August 1673, and the castle was damaged by aerial bombing on 24 March 1945.
The history
Konrad II Reiz von Breuberg built the castle around 1250, first recorded on 2 June 1252. It was sold to Hesse-Darmstadt in 1662 and the ruins were secured and rebuilt between 1835 and 1893.
What people report
Local tradition links Dippel's experiments to Mary Shelley's novel and tells of the knight Georg von Frankenstein slaying a dragon nearby; the castle has staged a Halloween horror spectacle every year since 1977.
That paragraph is reported tradition, not a claim about what is there. The history above it is sourced; the stories are recorded because people tell them.
Visiting
Burg Frankenstein 1, 64367 Mühltal, Germany