A short walk from the bottom of Essex hill you will find what locals call the "Frying Pan". A series of fortifications built by the Germans during their occupation of the island in World War Two.
The cache is hidden inside one of the bunkers and is in a small Tupperware container. You may want to bring a torch.
The whole area is well worth an explore, with stunning views of the nearby Longis beach and Fort Raz from the gun emplacements which gives an impression of how the beach defences worked