At a glance
North Wales has excellent wild swimming — mountain lakes in Snowdonia (Llyn Padarn, Llyn Gwynant, Glaslyn), river pools near Betws-y-Coed (Fairy Glen, Pont y Pair), and sea swimming on sheltered Anglesey and Llŷn Peninsula beaches. Mountain lakes are cold (8–14°C even in summer) — a wetsuit is recommended. Never swim alone in remote locations or in rivers after heavy rainfall. Wild swimming is legal in Wales on open access water subject to no specific restrictions.
The Best Wild Swimming in North Wales
Llyn Padarn, Llanberis — the most accessible large wild swimming lake in Snowdonia; a designated swimming beach at Llanberis; clean water and mountain backdrop. Warm relative to mountain lakes in summer (up to 18°C). The lake is 2.5km long and 30m deep; swim parallel to the shore rather than across.
Llyn Gwynant, Nantgwynant — a large, mountain-surrounded lake with a beach area and excellent swimming; below the Watkin Path approach to Snowdon. Water is clearer and colder than Llyn Padarn. The view across the lake to the Snowdon ridge is exceptional. A campsite operates at the lake shore in summer.
Glaslyn, Snowdon — the high mountain lake below Snowdon's east face; reached by the Miners' Track (2 miles from Pen-y-Pass). Dramatic position at 600m; very cold (8–10°C); emerald-green water from copper minerals. Popular with experienced wild swimmers; not recommended for beginners or without a wetsuit.
Fairy Glen, near Betws-y-Coed — a narrow gorge pool on the River Conwy, 1 mile south of Betws-y-Coed; accessible on a footpath (small fee for the landowner-maintained path). Popular and sheltered; warmer than mountain lakes in good summer weather. Get there early in summer to avoid crowds.
Llyn Tegid (Bala Lake) — Wales's largest natural lake at 4 miles long; Bala town on the north shore; good swimming from the town beach. Home of the gwyniad (a unique Ice Age fish species found nowhere else in the world). The lake's size means it can have significant wind chop — swim in sheltered weather only.
Trearddur Bay, Anglesey — sheltered sea swimming; warm coastal water (16–20°C in summer); rock pools and clear water. No lifeguard cover; tide awareness essential. One of the best sea swimming locations in North Wales.
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Frequently asked questions
Wild swimming is legal in Wales under the right of access to inland water introduced through Welsh Government legislation. In practice, swimming in the mountain lakes and rivers of Snowdonia has been tolerated and practised for generations. The key constraints are: some specific stretches of river may have landowner restrictions; several reservoirs have no-swimming rules for water quality reasons (Llyn Brenig, Llyn Celyn); and some locations have specific safety notices due to known currents or depth. Respect any no-swimming signs and avoid reservoirs. Lakes (llyns) and rivers on open access land are generally freely accessible.
Llyn Padarn at Llanberis is the most accessible large swimming lake in Snowdonia — it has a designated swimming area at Llanberis Beach with car parking, and the water is clean and generally calm. For a wilder experience, Llyn Gwynant in Nantgwynant (between Beddgelert and Pen-y-Gwryd) has a large beach area, clear water, and mountain scenery. Glaslyn (below Snowdon's summit) is a dramatic mountain lake at 600m with cold, clear water — accessed by the Miners' Track. All mountain lakes are cold even in summer (8–14°C); a wetsuit is recommended for prolonged swimming.
The Betws-y-Coed area has several river swimming spots. The Conwy River below Pont y Pair bridge in Betws-y-Coed village has pools used by swimmers in summer. Fairy Glen — a narrow gorge accessible on a footpath 1 mile south of Betws-y-Coed — has a pool below small falls, popular with local swimmers. The River Llugwy below Swallow Falls has pools accessible from the riverside path. Rivers in North Wales run cold and can rise rapidly after rainfall — never swim in rivers in flood conditions.
Mountain lake swimming in Snowdonia is generally safe in good conditions but carries risks that should be managed. Key safety considerations: water temperature (mountain lakes rarely exceed 14°C even in summer — cold water shock is a risk for unprepared swimmers); no lifeguard cover at any wild swimming location; depth (some mountain lakes are very deep — Llyn Cowlyd is the deepest in North Wales at 68m); and access — some lakes require mountain walks to reach. Never swim alone in remote locations; always assess conditions on arrival; carry a dry change of clothes; tell someone where you are going.
Yes — many Anglesey beaches are suitable for sea swimming. Benllech and Red Wharf Bay have shallow, sheltered water safe for swimming at low tide. Trearddur Bay has clear water and a sheltered bay position. The coastal swimming is warmer than the mountain lakes (16–20°C in summer). Beware of tidal currents in the Menai Strait — swimming in the Strait is not recommended due to very strong currents. Bull Bay on the north coast and Silver Bay on the west coast are sheltered alternatives. Check local tide information before sea swimming.
For comfortable wild swimming in North Wales: a full wetsuit (3mm minimum, 5mm recommended for mountain lakes) significantly extends comfortable swimming time in cold water; a brightly coloured swim cap makes you visible from shore; tow float for open water safety; neoprene gloves and boots for mountain lakes. At minimum: a dry bag for clothes and valuables, a dry towel, and warm layers for after the swim. Cold water immersion (below 15°C) can cause involuntary gasping and loss of swimming ability within minutes — never jump into cold water without first acclimatising by gentle immersion.