Secret Areas (AS2R) - Mission 4
See note at the end about seventh location.
Walk forward to reach the cooling block
There is a line of money at the room of the sixth secret. Just walk along.
I believe that the seventh secret is at the bottom-most (south) end of the map. Where there is a small closet entrance with two piles of money on both sides of the closed. I believe that you need to smash the wall behind that closet.