This is a simple one-stage multi.
The first stage is off the busy road with safe parking
You will be (parked or standing) looking at two powerful structures connected to other powerful structures heading west.
There are numbers on these structures easily visible from where you are parked.
You are interested in the vertical numbers (not the horizontal, STR #).
The correct coordinates for the cache location is simply calculated with the following formula:
S = 27 35.140 + (plus) the vertical number on the Northern structure (RHS)
E = 153 09.118 - (minus) the vertical number on the Southern structure (LHS)
There is a small FTF Prize.