The Kiepenheuer Institute for Solar Physics (KIS) conducts experimental and theoretical investigations of physical processes on and within the Sun. Its headquarter is in Freiburg, Germany. The KIS operates the german solar telescopes at Teide Observatory on Tenerife (Spain) where most of the scientific observations are performed. KIS offers lectures on astronomy and astrophysics at Freiburg university and trains young scientists. The magnetic field of a sunspot guides magnetohydrodynamic waves toward higher atmospheric layers. In the upper photosphere and lower chromosphere, wave modes with periods longer than the acoustic cut-off period become evanescent. The cut-off period essentially changes due to the atmospheric properties, e.g., increases for larger zenith inclinations of the magnetic field. These relations were now employed to develop a novel technique of reconstructing the magnetic field inclination on the basis of the dominating wave periods in the sunspot chromosphere and upper photosphere.