The largest all weather Tennis Court in the world is located in Keferloh, Prior to entering the gate to Munich. Enjoy the variety of the sport of Tennis on over 70 courts, in winter there are 30 courts available, 10 individual courts, 10 Portable warmed Tent courts with 2 courts each.
Currently these are tennis courts (the satellite image is a bit old) where you can learn to play tennis for $6 per hour. The tennis coach is called Danko and he is a great teacher.