You are looking for a bison tube disguised inside of another container. You will have to be very stealthy as GZ is viewable by muggle housing.
Looking for this cache at night would be like finding a needle in a haystack, so it is recommended you find it in daylight.
Parking can be found at Mainway Recreation Centre, there's a trailhead that leads into GZ from the corner of the parking lot. Parking can also be found on Kryzan Drive (I have included additional waypoints for both). Long sleeves and pants are recommended as there are tall grasses and some prickly bushes, along with a few blackflies in the summer months. Take a moment and enjoy the scenery while you're searching for the cache, you might even see a few ducks/ducklings milling about in the pond.
Good luck and happy caching! :)
Congrats to Custodio's for the FTF!
P.S. - Please refrain from posting pictures of the container and the hide itself with your log. I've had to delete a few pictures from logs since the start of this listing that are blatant spoilers of how it's hidden. Thank you!