Letterboxing is another form of treasure hunting that uses clues to direct hunters to a hidden container. Each letterbox contains a stamp which is the signature for that box. Most letterboxers have their own personal stamps and personal logbooks. They stamp the letterbox logbook with their personal stamp, and use the stamp contained in the letterbox to "sign" their personal logbook.
Letterbox hybrids are a mixture of letterbox and geocache. They should contain a signature stamp that stays with the box, and they must conform to the guidelines for geocaches and therefore must contain a logbook and involve GPS use as an integral part of the hunt. A letterbox hybrid cannot be designed to be found using only clues. Whether or not the letterbox hybrid contains trade items is up to the owner. In most cases personal stamp and personal logbook are not necessary to be a seeker of a letterbox hybrid.
Safe parking for 1 car is available a couple of hundred yards uphill. Access to GZ should not be made via the field margin but instead follow the roadside footpath down the hill to the trailhead waypoint. Here the public footpath begins. From here head up the steps (avoiding face height nettles in the summer) and head down the field margin to GZ.