Llyn Cwm-y-ffynnon
Encyclopedia
Snowdonia
Snowdonia is a region in north Wales and a national park of in area. It was the first to be designated of the three National Parks in Wales, in 1951.-Name and extent:...
, below the summit of Moel Berfedd in Cwmffynnon. The lake's original name was Fynnon Mymbyr as outlined in Llywelyn ap Iorwerth's charter of 1198. As the name suggests the lake nestles in a short valley, a cwm, high above the Pen-y-Gwryd
Pen-y-Gwryd
Pen-y-Gwryd is a pass at the head of Nantygwryd and Nant Cynnyd rivers in Gwynedd, North Wales and a quarter of a mile from the boundary with Conwy in northern Snowdonia, close to the foot of Snowdon...
hotel. The lake is the source of the Nantygwryd (originally Y Mymbyr), river which in Welsh translates to Pen-y-Gwryd
Pen-y-Gwryd
Pen-y-Gwryd is a pass at the head of Nantygwryd and Nant Cynnyd rivers in Gwynedd, North Wales and a quarter of a mile from the boundary with Conwy in northern Snowdonia, close to the foot of Snowdon...
. Incidentally, Llyn Cwm-y-ffynnon is impossible to pronounce correctly.
Prior to 1198 the name Gwryd did not exist in the Mymbyr Valley or Dyffryn Mymbyr
Dyffryn Mymbyr
Dyffryn Mymbyr is a valley in Snowdonia, North Wales, approximately in length, and leading up from Capel Curig to the Pen-y-Gwryd hotel....
. This would suggest that the name "Gwryd" has appeared at a later date for whatever reason, for which there is limited data.
The river which flows from here forms part of the county boundary between Gwynedd
Gwynedd
Gwynedd is a county in north-west Wales, named after the old Kingdom of Gwynedd. Although the second biggest in terms of geographical area, it is also one of the most sparsely populated...
and Conwy county borough.