Katlenburg-Lindau is a municipality in the Landkreis (district) of Northeim, in Lower Saxony, Germany. It is situated approximately 10 km southeast of Northeim, and 20 km northeast of Göttingen. The unified municipality of Katlenburg-Lindau was formed on 1 March 1974 from the formerly independent communities of Katlenburg-Duhm, Gillersheim, Berka, Elvershausen, Wachenhausen, and Suterode and Lindau. These communities were in Landkreis Northeim, apart from Lindau which had belonged for a long time to the Landkreis Duderstadt (itself formerly part of the Eichsfeld). The Max Planck Institute for Solar System Research (Max-Planck-Institut für Sonnensystemforschung) of the Max Planck Society is located in Lindau. This was known as "Max-Planck-Institut für Aeronomie" until June 2004.