Length of made track running east north east from Dyffryn Mymbyr house between SH 69520 57280 and SH 69757 57389. Between 2 m and 3 m wide. Substantial but roughly built boulder revetment along the down hill edge built up by up to 1.5 m in places. Cut in by 0.5 m along the up hill edge. Directly to the east of Dyffryn Mymbyr house two slate slab bridges take the track across streams. Where the track crosses a stream at SH 69592 57320 is a bridge constructed of large stone slabs 1.35 m by 1 m by 0.15 m thick, supported by dry stone wall abutments on either side of the stream. AD1890-91 Ordnance Survey map. K. Laws, Engineering Archaeology Services, 16th January 2005.