WARNING
There is currently a deer control program within Cleland Conservation Park and Mt Osmond Reserve, managed by the Department of Environment, Water and Natural Resources (DEWNR). Control operations, including shooting, may be undertaken any night between Monday and Thursday. Operations will not be undertaken on Friday, Saturday or Sunday nights or on Public and School Holidays. Signs have been placed at every major vehicle entrance gate into Mt Osmond
DO NOT attempt this cache on the nights that shooting may occur. Ensure at all times that you are visible (bright coloured clothing) and have plenty of lights on hand.
So, you've got your letter from Hogwarts, you've got your wand from Ollivanders and you've been sorted into your house. Now, do you dare to take a night time walk into the forbidden forest and see if you can cast a difficult spell?
The Patronus Charm is difficult, and many witches and wizards are unable to produce a full, corporeal Patronus, a guardian which generally takes the shape of the animal with whom they share the deepest affinity. You may suspect, but you will never truly know what form your Patronus will take until you succeed in conjuring it.
A Patronus is conjured as a protector, and is a weapon rather than a predator of souls: Patronuses shield their conjurors from Dementors or Lethifolds, and can even drive them away. They are also used amongst the Order of the Phoenix to send messages. Harry Potter's Patronus takes the form of a stag. This is what you will ultimately be seeking.
From the published coordinates, you will see the reflectors that will guide you into the forbidden forest. You will need to follow these for a few hundred metres. When you see three reflectors on a tree, look low for the tag that will tell you where the final cache is.
Be careful when seeking the stag, it is a little steep and a bit spiky near the final cache.