Schauenberg is a hill and ruined castle near Turbenthal, canton of Zurich, at 892m (2,927feet) elevation. There were fortifications since the Iron Age, and since the early 13th century, there was a wooden structure, in the 1250s extended to a massive keep. The fortress was destroyed in 1344. From 1622, Zurich maintained a system of beacons as a warning system, and signals from Schauenberg could be seen at Schnabel (Albis), Pfannenstiel, Tämbrig (above Hermatswil), Uetliberg, Lägern, Zürichberg, Mörsburg, Kyburg, Stammheimerberg and even Hohenklingen.