Much of the forest to the south of the image has been felled, leaving the usual appearance of devastation.
The Tywi Forest is a very extensive area of coniferous plantation established in the 1960s over what had been, in the main, open moorland. Abandoned post-Medieval settlements and Bronze Age monuments reveal that this landscape was more intensively populated and used in the past. With many of the trees being well over forty years old, felling is in progress in many parts of the forest, hence the good condition of many of the stony roads.
Note: sorry this is almost identical to
SN7954 : Forestry road on Esgair Gors, Ceredigion, taken later in the day. I'd forgotten that I'd already selected the first one.