Thunder Tower is an area that first appears in Chapter 5. This is the area that you fight the Fierce Pork Trooper for a second time, and where you get PK Flash. There is a map of the area that isn't too hard to understand, so you are able to navigate the area easily.
The Thunder Tower was made to punish those that thought freely and possibly against the Pigmask Army as they sought to control everyone's thoughts and actions. The Thunder Tower punished Flint, Lucas, Lighter, Fuel and Reggie.
Fierce Pork Trooper 2nd Time
Lucas learns PK Flash
Mr. Genetor Battle