(QNNA) Was this operation a:
- quarry, namely above ground, feeding pack animals and/or tramway?
- mine, namely underground, perhaps more likely to have a mining tramway?
The short answer is "yes". Diffwys, like many of the Blaenau quarries had both underground and overground operations. There are both pits and adits on the site. I am not sure if there was more surface or underground working though, I suspect the latter. The terms "quarry" and "mine" were not strictly applied in the slate industry. For example, Foel Grochan at Aberllefenni is generally referred to as part of "Aberllefenni Quarry" even though it was almost exclusively an underground operation. Dan Crow (talk) 13:35, 2 September 2015 (UTC)