Cefn Cyfarwydd is a ridge in Conwy county borough, north Wales. It is located above the village of Trefriw on the western side of the Conwy valley, and dramatically separates Cwm Cowlyd and the rugged mountains of the Carneddau from the greener, lusher Conwy valley.
The Welsh word cyfarwydd can mean either "familiar" (adj.) or "a story-teller, guide or expert" (noun). Cefn means "ridge".
'Cefn Cyfarwydd' therefore translates as either "familiar ridge" or "story-teller's ridge".
The ridge reaches some 500m in height, and covers an area of some 8 square kilometres, broadly 4 km long by 2 km wide. It runs in a largely SW - NE direction, and is relatively flat-topped, resulting in some wet pools and boggy patches, even in the summer months. Much of it is heathery moorland.
To the north-west it slopes down steeply to Llyn Cowlyd, and to the south-east to Llyn Crafnant and the Crafnant valley where, in places, these slopes have been forested. The south-eastern slope of the ridge is steeper than the north-western slope.
The north-eastern end of the ridge drops into the Conwy valley between Trefriw and Dolgarrog, whilst to the south-west it runs on to become Pen y Graig Gron ("top/end of the round stone"), then rises to the ridge of Creigiau Gleision ("blue-green rocks") (over 600m in height) and the Crimpiau. For much of its length it affords splendid views in all directions.
There is a trig point (triangulation pillar TP2074) recording a height of 419 m (1375 ft) at location SH7641664273. This can be easily viewed from Ffordd Cowlyd, the lane from Trefriw to Llyn Cowlyd, which crosses Cefn Cyfarwydd towards its northern end.
The trig point is, however, not at the highest point of the ridge. The highest point actually lies some mile to the south-west, where a cairn has been placed at a height of 503 m (1650 ft). This is just a little north of the remains of Lledwigan burial cairn, which probably dates to the Bronze Age.