On the edge of the castle grounds lies a narrow stone aqueduct, winding towards the cliffs and hills beyond Penwick. Once used to carry water from a distant spring into the heart of the school, it has long dried up. Now, only rainwater goes through the shallow channel. About a kilometer long and five meters wide, the walk is named for the unique magical phenomenon that happens there. Or, rather, the lack thereof. Spells cast within the space will simply fail, magically innate abilities such as The Sight no longer function, and lycanthropes don't transform into a werewolf during a full moon.