Affenkugel's Castle is a castle somewhere high upon a mountain, surrounded by water and inhabited by Klaus Von Affenkugel and his assistant Ludwig.
- It's unknown what the location of the castle is. Tommy and Gus could get there in a short distance to rescue Robotboy on their bicycles, so it looks like it is near The Bay Area. But in Six Million Euro Man it is near Moshimo's secret lab in the artic.
- Outside on the walls of the castle are red wires. These are the same red wires that can be found on Protoboy's head. What they are for, is unknown.