Take the path at the back of the Glen O' Dee hopital car park that heads West in to the woods.
Follow this path until you reach a wall
From the wall follow the path West for 20 paces until you reach two rocks on the edge of the path (north side)
Standing between the rocks with your back to the path walk forward 9 paces until you find a old tree stump.
The cache is in a ditch on the north side of the stump