Apart from the fact that Berra Tor is right on the egde of the common, the lanes around here are very narrow and although there is good parking at the end of the lane at N50 30.242 W4 08.690 most people do not venture this far over.
A better place to park is opposite the Longash garden center at N50 30.314 W4 07.213 from where it is just over a mile and a half walk along the top of the hill with great views across the Walkham Valley. As you approach the Tor you will notice the wall on the left hand side with a ditch running along the base. This was an iron age settlement and the field inside the wall is still called "Castle Field" by locals. There is no Public access into the field which is a scheduled ancient monument.
Settlement field and ditch
The cache is an ammo can which is hidden down the side of a large lump of granite. The lump of granite is hidden by a gorse bush so a stick and possibly a pair of gloves would be helpful.