The Sackpfeife is a mountain, 673.3 m above sea level (NHN),, in the Rothaar Mountains on the boundary of the counties of Waldeck-Frankenberg and Marburg-Biedenkopf in the German state of Hesse.On top of the forested mountain, which is a well known and popular recreation area, are the Emperor William II Tower, which offers views over the Rothaar highlands, the Biedenkopf Transmitter and a ski lift.