This is similar to my (now archived) cache GPs. However, whereas with that cache you had to pretend to follow the given path to GZ, in this case you can easily walk it.
Start at the given waypoint, go 100m due true west, turn 90° right, go 50m, turn 90° right, go 25m, turn 90° right, go 12.5m, turn 90° right etc., halving the distance you go after each 90° turn right.
As you pace it out, watch out for trees and traffic!
Cache is a camouflaged capped tube.
If you'd prefer to work out the coordinates of GZ, I assumed 1850m per minute of latitude, 1560m per minute of longitude.