Lake Hallwil would actually be the perfect place for an island. But the island on which the Lords of Hallwyl built their castle lies a kilometer beyond in the tiny Aabach. The castle island is also artificially heaped up. But the stories associated with this island are far too exciting not to be told for such reasons. For ranger Bruno Fürst, nature on the Aarbach is grand opera: the play of light on the emerald-green water, the chirping of the nightingale and pond warbler - for him, there is no more perfect show...