Castle Finster is an old castle in Germany.
Construction began on the castle in 1436, but it was actually completed by its third owner, Freiherr Amsel, around a century later. He intended it to be a home he could pass down through the generations of his family. Unfortunately, only one of his four children, Else, survived into adulthood, and even she died young, beginning the the long tradition of the castle's dark history. The Freiherr shut himself away in the castle until he died.
The castle continued a dark tradition of girls going missing. They were all girls who looked like Else, and all were said to wear the necklace that was an emblem of office. Renate's map says that five girls went missing, but the book Anja has that is called The Captive Curse states that there is only historical evidence for Else's disappearance. The townspeople blamed the legendary monster for both the girls' disappearances and the deaths of their livestock. This legend eventually even inspired someone to build two puzzles in the castle's deepest dungeon that were based on the legend in order to allow someone to escape confinement.
The castle also has a glassblowing shop. It burned down in 1923, but was rebuilt with better safety standards. Tours are given of it and of the dungeon. One year, one of the dungeons collapsed while Karl was conducting a tour and people came close to dying, adding to his and the castle's bad luck. The portrait of the Freiherr's daughter was also damaged by fire in 2006, and it had to be reconstructed without the painter's initials.
By 2011, the castle has formed quite a community, with its own newspaper, Bürgermeister, and people living in the courtyard. Every year there is a celebration of one more year without any monster sightings called Die Ungeheuerlichtkeit Nacht Festival. The castle is owned by Markus Boehm, a wealthy investor who doesn't seem to care that much about the place but nevertheless calls Nancy to investigate the latest monster rumor, since he has other investors coming over soon.
Nancy discovers that the castle's castellan, Anja, had been preparing to set up a publicity stunt for the castle in which she, the "monster" killed Nancy, who would be dressed as the young girl, and was then going to frame Markus (her ex-boyfriend) for it with incriminating emails seemingly from him that she faked in order to ruin him. Nancy traps Anja in the dungeon, having taken her notes so that she couldn't solve the escape puzzle, and has her arrested. Markus is too stunned by the incident to keep the castle and sells it once again. Die Ungeheuerlichtkeit Nacht Festival is replaced with the Finster Festival to celebrate the castle's good times, because the residents are no longer fearful.
- Finster is the German word for "dark".