Llyn Llydaw
Llyn Llydaw is a long, narrow glacial lake situated high on the eastern flank of Snowdon, the highest mountain in Wales and England, lying within the Snowdonia National Park. At an elevation of approximately 445 metres above sea level, it occupies a dramatic cwm — a glacially carved cirque — beneath the formidable ridgeline of Crib Goch and the Snowdon Horseshoe. The lake stretches roughly 900 metres in length and is one of the most photographed mountain lakes in Britain, its dark, mirror-still surface reflecting the towering crags and scree slopes that surround it on three sides. It is notable not only for its wild beauty but also for its prominent role in the network of paths ascending to the summit of Yr Wyddfa (Snowdon), making it a landmark that the vast majority of Snowdon's visitors encounter on their journey.
The lake has a deeply layered history, both geological and human. It was formed during the last ice age as glaciers gouged out the bedrock of the cwm, leaving behind a natural hollow that filled with water from the surrounding slopes. In terms of human history, Llyn Llydaw became industrially significant during the nineteenth century when copper mining operations expanded in the area. The Brittania Copper Mine, whose ruined remains still stand on the lake's southern shore, was among the most productive copper mines in Wales during its peak years, and ore was transported across the lake via a simple causeway — that causeway still exists today and is used by walkers on the Miners' Track, one of the principal routes up Snowdon. The submerged remains of old mining infrastructure lie beneath the lake's surface, giving it an additional layer of industrial heritage invisible to the casual eye.
Llyn Llydaw is also steeped in Arthurian legend. According to Welsh tradition, this is one of several lakes identified as a possible site where Sir Bedivere cast Excalibur into the water after the Battle of Camlann, and where King Arthur's body was borne away by boat. While these legends are not attached to Llyn Llydaw alone — other Welsh and Cornish lakes make similar claims — the remote, otherworldly atmosphere of the lake lends the story a peculiar credibility when you are standing at its edge. The stillness, the depth, the surrounding cliffs, and the way mist drifts across the surface in autumn and winter all conspire to make it feel like a place where myth and landscape have genuinely merged.
In person, the physical character of Llyn Llydaw is striking and slightly austere. The water is extraordinarily clear and very cold, tinted a deep blue-black by depth and the dark Cambrian volcanic rock of its bed. The surface can shift rapidly in mood: glassy and tranquil on a calm morning, whipped into small whitecaps when wind funnels down from the summit ridges. The sound of the lake is defined by wind and running water, particularly from the outflow stream, and on still days by the distant calls of ravens that patrol the crags above. The air at this altitude carries a rawness even in summer, and the surrounding landscape of scree, grass, and bare rock gives the place a primeval, stripped-back quality that is worlds away from the pastoral valleys below.
The scenery surrounding Llyn Llydaw is some of the most dramatic in Britain. To the north rise the jagged teeth of Crib Goch, to the west the summit pyramid of Snowdon itself, and to the south the long ridge of Y Lliwedd, a massive and somewhat underrated peak whose dark cliffs plunge almost directly into the lake's eastern end. This horseshoe arrangement of peaks means that Llyn Llydaw sits at the centre of one of the finest mountain amphitheatres in the country. Pyg Track walkers look down onto it from above, while Miners' Track walkers pass along its northern shore at water level, crossing the causeway and pausing at the ruins of the mine buildings. The smaller lake of Glaslyn lies higher up in the cwm above, connected to Llyn Llydaw by the route continuing toward the summit.
For visitors, the most straightforward way to reach Llyn Llydaw is via the Miners' Track, which begins at the Pen-y-Pass car park at the top of the Llanberis Pass, at an elevation of around 359 metres. Pen-y-Pass is served by the Snowdon Sherpa bus service, which is strongly recommended given that the car park has a very limited number of spaces and fills extremely early on popular days. The walk from Pen-y-Pass to the lake along the Miners' Track is approximately two miles, mostly on a well-graded stone path, and involves relatively modest elevation gain to reach the lakeshore, making Llyn Llydaw accessible to walkers of moderate fitness who may not intend to continue to the summit. The path is well-marked and well-maintained, though it can be slippery in wet or icy conditions.
The best time to visit is a matter of personal preference and tolerance for crowds. Summer brings the largest numbers of walkers, and while the days are long and the weather most reliably kind, the Miners' Track can feel busy. Autumn is arguably the finest season: the light turns golden, the crowds thin, mist settles over the water in the mornings, and the surrounding slopes take on reddish and ochre tones. Winter visits require proper equipment, experience in mountain navigation, and awareness that snow and ice can make even the lower sections of path hazardous. Spring brings snowmelt from the ridges, swelling the outflow stream and giving the lake a particularly full and dynamic character.
One lesser-known aspect of Llyn Llydaw is that it has been used as a reservoir, with its water level artificially raised by a small dam to serve the water supply needs of the former mining operations and later for other purposes. This manipulation of the lake's level is not immediately obvious to visitors, and the dam structure blends quietly into the landscape. The lake also holds populations of brown trout and Arctic char, the latter a cold-water species that is a glacial relict — a remnant from the post-ice age period when these fish colonised the newly formed mountain lakes, and which have been isolated in these upland waters ever since. The presence of Arctic char in Llyn Llydaw is considered significant from a conservation and ecological standpoint, as the population represents a genetically distinct lineage adapted to this specific environment.