The exact origin of Sichelstein Castle is unknown. It is known that in 811 two Saxon nobles had to leave their homeland because they were devoted to Charlemagne. The son of the Bishop of Verden, Amelung, settled in nearby Benterode. It is not known who founded the castle in Sichelnstein, but Amelung's great-grandson bore the title Wittilo von Sichelnstein. The Sichelstein line died out in 1239 with Bardo stabbing his wife. As punishment, all his property fell to the Guelphs and he died alone in his castle. In the following centuries, the castle changed hands several times between Hesse and Brunswick. Otto the Quade in particular waged war against his cousin Hermann I of Hesse from here, which is why he had Sichelnstein heavily fortified. The end of Sichelstein Castle is not documented, but it was probably destroyed in the Thirty Years' War and used to build up the towns of Sichelstein and Benterode.
The imposing ruin is just the basement of the former castle. All habitable parts are no longer visible today. You can walk around the ruins and also take a look into the very deep moat. An information board and drawings explain the history of Sichelnstein Castle. There is a small open-air stage inside the castle, but access is blocked. All in all, the astonishingly large and mighty ruins in the rather small Sichelnstein are a highlight that should not be missed.