You are looking for a small camouflaged round lock-n-lock container.
Berrygrove Woods is an ancient, semi-natural woodland that has existed on this site for more than 600 years. An uncommon array of plant species can be found here. Bluebells and Wood Anemone appear in late spring before the trees are in full leaf, shutting out much of the sunlight. Evergreen Wood Spurge thrives under the woodland canopy and can be found amongst the Bracken later in the year. The woods boast a range of tree species with a wide age structure which in turn supports a wide variety of wildlife. While visiting these woods you may see Britain’s smallest songbird, the Goldcrest which uses its narrow beak to pick insects from between pine needles. The busy Treecreeper may be seen using small hops to progress up tree trunks in a spiral fashion searching for food. Sunny path edges provide ideal places for butterflies and a woodland pond is home to frogs and a variety of dragonflies and the scarce Purple Moor-grass can be found in the wetter, heathy areas in the wood.
... to get to the next cache in the series, continue straight on into the woods turning onto another trail at the point at which your GPS arrow is pointing almost directly to the left and try to remember if you locked the car... are you sure?