At a glance
One of the finest wild swimming spots in Wales — a clear glacial lake in the Nantgwynant valley with Snowdon reflected in its waters. Free; roadside access from the A498. National Trust campsite on the shore. No lifeguard; wetsuit recommended. LL55 4NL.
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.
About Llyn Gwynant
Llyn Gwynant occupies the lower Nantgwynant valley — a glacially carved trough running south from the col at the head of the Llanberis Pass — between the village of Beddgelert and the Pen-y-Pass car park. At 800 metres long and surrounded by steep, craggy hillsides, it is one of the most scenically enclosed lakes in Snowdonia: shut in by mountains on three sides, with the Yr Wyddfa (Snowdon) massif visible from the northern shore on clear days.
The lake is fed by the Afon Glaslyn as it flows south from the summit cwms of Snowdon, carrying cold, clear water from the uplands. The quality of the water, the dramatic setting and the accessibility from the A498 road (with lay-by parking) make it the most popular wild swimming destination in the Beddgelert area and one of the most visited in all of Snowdonia.
A National Trust campsite on the southern shore puts swimmers within seconds of the water. Campers here wake to a view that was painted by artists and described by travellers for centuries before the age of cars — the lake, the valley walls, and, on clear mornings, the mountain reflected in the flat water. The campsite is in high demand and should be booked well in advance for summer visits.
Find it on the map
Frequently asked questions
Llyn Gwynant is in the Nantgwynant valley on the A498 between Beddgelert (3 miles south) and Pen-y-Pass (3 miles north). Use postcode LL55 4NL for the southern end of the lake. The lake is visible from the road and accessed via roadside lay-bys. The Snowdon Sherpa bus (route S2) stops at Nantgwynant — one of the few Snowdonia wild swimming spots accessible without a car.
Llyn Gwynant is one of the more popular and relatively benign Snowdonia wild swimming locations. The water is clear, the entry is straightforward from the grassy/rocky bank, and the lake is sheltered from most winds by the surrounding valley walls. It is still a mountain lake — cold year-round (12–18°C in summer), with no lifeguard, and cold water shock is a risk. Never swim alone, tell someone where you are going, and use a wetsuit outside the warmest months.
Yes — the National Trust operates a popular campsite directly on the southern shore of Llyn Gwynant. Campers can walk to the water's edge in seconds, making it one of the most convenient wild swimming camping locations in Wales. The campsite is in high demand in summer and should be booked well in advance at nationaltrust.org.uk. Facilities include toilets and a small shop. Campfires are not permitted.
Yes — the view from the northern end of the lake looks directly up the Nantgwynant valley to the Yr Wyddfa (Snowdon) massif, with the Watkin Path and surrounding ridges visible. On calm mornings, the mountain is reflected in the lake — one of the most iconic views in Snowdonia. The Watkin Path, one of the six main routes up Snowdon, starts from the A498 at the southern end of the valley (approximately 3 miles south of the lake).
As a glacially carved mountain lake with inflows from the surrounding hills, Llyn Gwynant is cold year-round. Summer temperatures (June–August) typically reach 12–18°C. In spring and autumn, expect 8–12°C; in winter, the lake can fall to 4–6°C. A full wetsuit is recommended for anything longer than a brief dip, and essential outside the summer months.
Early morning before 8am is the best time — the lake is mirror-calm, the light is exceptional, and the lay-bys have not yet filled with cars. The Nantgwynant valley is heavily visited in summer (it is the main road to Pen-y-Pass) and the lay-bys fill completely by mid-morning on good weekends. Arriving early also gives the best chance of seeing the mountain reflected in undisturbed water.