Llyn Dulyn (Black Lake)

Llyn Dulyn is a small cirque lake bound by the high cliff faces of Garnedd Uchaf and Foel Grach on the edge of the Carneddau mountains. It is approximately 33 acres in area, has a mean depth of 104 feet, and is 189 feet at its deepest point. The lake has a dam which was constructed in 1881, and it now serves a reservoir for Llandudno. It is one of the lakes where the Arctic Char can be found in Wales.

It is said that there was once a causeway out into the lake (this will now submerged due the raised water level), and it was believed that anybody who visited the causeway on certain festival days, i.e. Midsummer’s Eve, May Day and All Hallow’s Eve would be able to see who was going to die in their community during the next year. At the end of this causeway was a red coloured rock known as ‘Yr Allawr Goch’ or the ‘Red Altar’. It was said that anybody who wet this rock would cause it to rain.

An account translated from a Welsh magazine printed in 1805:
“There is a lake in the mountains of Snowdon, called Dulyn, in a rugged valley, encircled by high steep rocks. This lake is extremely black, and its fish are deformed and unsightly, having large heads and small bodies. No wild swans are ever seen alighting upon it (such as are on all the other lakes in Snowdon), nor ducks, nor any bird whatever. And there is a causeway of stones leading into this lake; and if any one goes along this causeway, even when it is hot sunshine, and throws water so as to wet the furthest stone, which is called the Red Altar [yr Allawr Goch], it is a chance if it do not rain before night. Witness, T. Prys, of Plas Iolyn, and Sion Davydd, of Rhiwlas, in Llan Silin.”

Llyn Dulyn and the Red Altar may relate to the fountain, as depicted in the Mabinogion’s (The Lady of The Fountain).
“And Owain followed the road, as Kynon had done, till he came to the green tree; and he beheld the fountain, and the slab beside the fountain, with the bowl upon it. And Owain took the bowl, and threw a bowlful of water upon the slab. And, lo, the thunder was heard, and after the thunder came the shower, much more violent than Kynon had described, and after the shower the sky became bright”.