At a glance
Llyn Geirionydd (LL27 0JH) is a free upland wild swimming lake in Gwydir Forest above Trefriw — clear water, wooded shores, Taliesin monument nearby. Not a water supply reservoir — swimming and kayaking permitted. Very limited parking (arrive early). 2 miles from Trefriw by road. Combine with Llyn Crafnant (2 miles away) for a forest lake day.
About Llyn Geirionydd
Llyn Geirionydd sits in a shallow basin in the Gwydir Forest above Trefriw — a lake with the quiet, contained character of a place that has not been widely publicised and remains quieter than it might otherwise be. The surrounding forest has grown up around it without entirely enclosing it, and the views across the water from the western shore encompass the wooded hillsides above and a strip of sky that suggests the openness of the moorland beyond.
The lake has literary associations that date back to the earliest period of Welsh poetry. Taliesin — the 6th-century Welsh poet whose name is attached to one of the earliest collections of Welsh verse — is associated in tradition with this part of the Conwy Valley. A monument to him stands on the hillside above the eastern shore, reached by a short path from the lake. The legendary Taliesin of Welsh myth is a figure of magical transformation; the historical poet behind the legend may have been a genuine court bard of the 6th century.
As a wild swimming destination, Llyn Geirionydd has a significant advantage over many Snowdonia lakes: it is not used for water supply, which means swimming and non-motorised boating are permitted without restriction. The water is clear and relatively accessible from the western shore. In summer, on warm days, the lake draws swimmers from the Conwy Valley and beyond.
Safety information
Wild swimming carries serious risks. Never swim alone. Tell someone where you're going and when you'll be back. Enter the water gradually to avoid cold-water shock. Know your exit point before you start. Wear a tow float and consider a wetsuit even in summer — Welsh lake and sea temperatures rarely exceed 16°C.
In an emergency call 999 and ask for the Coastguard (sea) or Police / Mountain Rescue (lakes & rivers). Nearest A&E: Ysbyty Gwynedd, Penrhosgarnedd, Bangor LL57 2PW. Tel: 01248 384 384.
Find it on the map
Frequently asked questions
Llyn Geirionydd is in the Gwydir Forest above Trefriw village in the Conwy Valley, approximately 2 miles by road from Trefriw and 4 miles from Llanrwst. The road from Trefriw climbs steeply into the forest — the lake is at a higher elevation than the nearby Llyn Crafnant. There is very limited roadside parking near the lake (postcode LL27 0JH). Arrive early in summer to find a parking space.
Taliesin was a legendary 6th-century Welsh poet — one of the earliest named poets in Britain, whose work survives in the collection known as the Book of Taliesin. He is associated in Welsh tradition with the Conwy Valley area, and Llyn Geirionydd in particular — there is a monument to him on the hillside above the lake. The historical Taliesin may have been a real court poet from around 550 CE; the legendary Taliesin is associated with magical transformation and wisdom. A short walk from the lake finds the monument.
Yes — Llyn Geirionydd is a popular wild swimming lake with clear, relatively warm (by Welsh upland standards) water in summer. The lake is not used for water supply (unlike nearby Llyn Cwellyn and Llyn Cowlyd), making it freely available for swimming. The western shore has the easiest access to the water. Always assess conditions before entering, never swim alone, and be aware that the water will be cold even in mid-summer.
Llyn Geirionydd is used by kayakers and canoeists — non-motorised boats are permitted on the lake. The calm, sheltered water in the bowl of the Gwydir Forest makes it ideal for flat-water paddling. Launching is from the shoreline — there are no formal facilities. Check Natural Resources Wales guidance on water access rights and any seasonal restrictions.
Yes — the two lakes are approximately 2 miles apart across the Gwydir Forest ridge and can be combined in a forest walk of approximately 3–4 miles. NRW waymarked paths connect the two lakes through the forest. Alternatively, drive between them (allow 10–15 minutes on narrow forest roads). Llyn Crafnant has the café and the easy circular walk; Llyn Geirionydd has the wilder character and the Taliesin monument.