I instinctively avoided the path marked Challenge and Adventure, but, after much wandering found that was the route to the very well hidden squirrel hide.
Taking this path towards Signal House, turning left through an unmarked gate by some more signs I eventually found a post with this symbol on.
The signs had come off, but turning right leads past this carved squirrel.
At the next squirrel, a left turn leads to the hide.
The hide was in fact so well concealed that no squirrels actually located it during the time I was there, so I gave up and retraced my steps to the car park.
This is my 'camping in the Canadian Rockies' picture...almost!
From the car park a long avenue leads around the western edge of the forest.
Parkhurst Forest is one of the country's most ancient woodlands, a medieval royal hunting ground and the oak plantation dates from Napleonic period, when what is now the prison was a barracks and there was a need for timber to build warships. There are nationally rare species of pasture woodland and open heath grassland species, giving a pleasing variety as you walk through different areas of the forest.
The last hundred years has seen the planting of many conifers, with much of the forest now composed of Spruce, Scots and Corsican Pine, Firs and Cypress, but there are still patches of the mature Oak and Beech dating from pre-enclosure times.
Fortunately there were quite a few dog walkers around who knew their way around better that I did.
Unfortunately, I hadn't found this useful map, available here from the Forestry Commission website.