I got this idea from a cache in Gippsland, not that that will help you.
The location of this cache is an urban forest almost in the middle of town. Composed entirely of pine trees (pinus radiata I believe), it is a nice copse, although it could get spooky at night. Given it is a few years old now, it was presumably planted when the town was a lot smaller, and it has now grown around this area.
You are looking for a small Bison tube in a container about the size of several of them put together. Its not too hard but the trees will play around with your GPS/phone, and picking it from the surroundings could be a small issue.