The URGENT TRAINING GRD, is the place where you can level up or train units faster than the normal completion of missions. More like the Daily Events, each unit affiliation is separated or scheduled per day. You can try the Urgent Training Grd map by going to the Special Event section of the game. See image below in red box for the exact location.
If you want to know more about the training ground you can visit the links provided below: Iron Bulls, Aqua Marines, Gorilla Warriors, Panzer Unz Fire, Desert Skulls & G.O.O.D.
Click or Tap sphere to open a specific Training Grd information.