I did the “round trip”:https://www.silvertraveladvisor.com/review/attraction/200650 on the Welsh highland Railway in October 2019. This is one of a series of short reviews with pictures of different parts of the line.
After Rhyd Ddu, the line continues to drop through the isolated Gwyrfai valley. This is bare moorland with the occasional sheep. It is hardly surprising there wasn’t enough traffic to make the original line viable. The railway runs above the shore of Llyn Cwellyn, which was dammed at the northern end to provide a reservoir supplying drinking water for Gwynedd and Anglesey. To the left is the bare rocky mass of Craig Cwmbychan with Mynydd Mawr behind. To the right, steep slopes climb to Moel Eilio. On a dull day it is decidedly atmospheric.
As the line continues to drop, crossing the river several times. The line passes close to the isolated settlement Salem and then the tiny church of St Garmon. The valley bottom is increasingly flat and wide with sheep and cows grazing as the steep mountain sides are left behind.
Waunfawr Station is a short distance south of the settlement. The railway now leaves the A4085 and follows the river valley down through mixed deciduous woodland. There are views across the Menai Strait to Anglesey. At Dinas the line picks up Lon Eifion cycle way which drops down through the woods to Caernarfon. Trees mask most of the views but at one point there is a wonderful view of Caernarfon Castle seen through a gap in the trees.