Other than the well-known international airports in Bavaria and the smaller glider airfields, there are so-called regional airfields building the main part of decentralized aviation.
Like Munich MUC or Berlin TXL and SXF, they have an IATA-Code, but are not used for regularly scheduled passenger flights. Such regional airfields are located in e.g. Kassel, Kempten or Augsburg.
This poster deals with the advantages and disadvantages of keeping a regional airfield around, especially when it is only partly used. It also shows a map of the small airport, tells about former destinations and about the airfield's costs.