Use the Beetle to blast the gold and silver walls, then use someone who can manipulate electricity like Thor,Storm,or Havok to charge the three panels with electricity. One each behind the walls and another on the ceiling.
See this topic for a better description http://www.gamefaqs.com/boards/696965-lego-marvel-super-heroes/67588759
There is a secret cave near by and the token is actually BELOW the park. There should have been a little down pointing white triangle on the map, but I guess the elevation change isn't significant enough.
"Man how to people figure this stuff out? A rubber band on the R button." - HYPERMECHA