The cache is the size of a 35mm film canister but is well hidden so you have to look carefully for something unusual.
Please be careful to repace the cache exactly as you found it or you might just see the water level in the reservoir drop... is this a clue?
This is a lovely place for a summer evening walk with the dog. Enjoy the climb up the hill through the meadow then turn around and watch the sunset over the water - lovely!