The upper East Dart valley is one of the most inaccessible parts of Dartmoor but is probably the inner heart of the moor. East Dart head consists of a large bowl that drains a substantial part of high Dartmoor. There are 3 or 4 tributaries of the river that join up and merge at the southern edge of the bowl. East Dart head can be a very lonely and eerie place to be.Cranmere Pool is a small depression in the peat set in the northern half of Dartmoor at grid reference SX604858 SX604858. It is approximately 0.5 km north west of the source of the East Dart and is effectively the head of the West Okement which feeds Meldon reservoir. The only time there is standing water is after heavy rainfall. It lies within the Okehampton Artillery range, one of the Ministry of Defence ranges. A military access road which made it possible to drive to within one kilometre of Cranmere Pool has now (2010) been closed for civilian use (although the road surface is now very worn in places). It is possible to park at one of the military observation posts (OP 15). Cranmere pool is the location of the first letterbox. The Victorian walker William Crossing relates in his Guide to Dartmoor that a well known Dartmoor guide (James Perrott) from Chagford placed a bottle for visitors cards at Cranmere Pool on the northern moor in 1854. That is a pic of Me taken a couple of years ago, not sure if we will reach there again,it is very near East Dart Head, the source of the River in my latest uploads.