Easily missed, this granite rock, on the Abbot's Way, is inscribed 'BB Broad Rock' and was a boundary stone for Blachford Manor. Its location along with Arme Head Stone is very isolated on the South Moor. The most accurate Grid Ref is SX 61850 67243.
Included in Ken Ringwood's 'Dartmoor Tors and Rocks' book from 2013 this is essentially nothing more than a large flat earth bound boulder near to Aune Head on the Abbot's Way upon which is inscribed the legend 'BB/Broad/Rock/'. We learn from the expertise of Dave Brewer (DB 1986) that the boundary is marking Blachford Bounds for the Manor. In Part 2 of The Forest of Dartmoor (page 55) the Reverend H. Hugh Breton (1932) gives this fascinating insight of a once sign at the site; "A pole standing up with a notice board fixed to it. This is Broad Rock, the Cranmere of the southern quarter of the moor."
Strangely he makes no mention of the inscription on the rock and we have to wait some 50 years or so later for DB to describe it properly complete with a helpful GR and a nice sketch of the stone in his early account of Dartmoor Boundary Markers. Always difficult to espy in an otherwise featureless expanse of moor it is hoped the 10 figure GR will help with the discovery of Broad Rock for future visitors.