Two parallel fences running parallel delineating a field to the north-east of Abergynolwyn, consisting of crawiau or rough slabs or planks of slate (`craw? = a piece of waste slate) of varying height placed upright in the ground several inches apart and held together with wire. This style of fencing is distinctive to the slate-producing districts of Gwynedd (although it does appear elsewhere in England and Wales, usually constructed in areas or by individuals connected with that district) where it is attested as far back as the late-eighteenth century.

(Sources: David Gwyn, Welsh Slate: Archaeology and History of an Industry (Aberystwyth: RCAHMW, 2015), p. 40)
A.N. Coward, RCAHMW, 09.10.2018