This cache is on the Forest boundary, but not one of the original markers. It has been set as a waypoint between Mystor and Mewyburgh, and although not mentioned in the 1240 perambulation, it is included on the route taken by the Forest surveyors in 1609. More details about the Perambulation can be found on the cache page for the Dartmoor Forest Bonus. On the front page of the logbook is an adjustment to be made to the Bonus co-ordinates, which you will need to find the Bonus.
When the tinners first started exploiting Dartmoor’s natural resources, there were many streams and rivers that started their courses from small lakes in the peat bogs. In order to make life easier for the tinners, they often set about draining these lakes to dry out the bogs. What was left behind was a dryish depression in the peat, which came to be known as a “dead lake”, and there are a few scattered across the moor. This also explains why there are so many places on the moor with “lake” in the name, where no lake currently exists. The drainage excavations dug by the tinners at this dead lake can still be seen today.
If doing this cache as a standalone, the best parking is at Baggator (waypoint below), and this will give a good stepping off point to other caches in the area. If doing the Perambulation as a route, the next point on is Mewyburghe, and the going is relatively good to there, although there is a patch of blanket bog on the top of Cocks Hill. As you crest Cocks Hill, you get a great view of the northern tors, and the chimney stack of Fur Tor to your right.
The next point on the perambulation route is White Barrow, which has been known as Mewyburghe. This point is currently occupied by one of Dartmoor Dave's caches, Heads of the Rivers Trek 5 White Barrow, and he has kindly allowed me to place a clue for this series bonus inside it.
IMPORTANT: This cache lies within the Merrivale Range, please see the Dartmoor Firing Notices to see when the range is active.