At the top of the public footpath, going across the Grove (a space perfect for picnics in the summer!), you are looking for a signpost pointing to 'Whitehall Road' - just past this post, you will see another green post. You are looking for a camouflaged tupperware box on the ground. If you continue on the path, you will end up in the historical town of Harrow on the Hill -! Happy Caching!