At a glance
Afon Glaslyn wild swimming in Nant Gwynant (LL55 4NQ) — clear mountain river pools near Pont Bethania, below Snowdon. NRW pay car park at Pont Bethania. Free river access. Best June–September. Sherpa bus S97 from Beddgelert. Combine with Llyn Gwynant (1 mile) and Llyn Dinas (1 mile south). Bring a dry bag and warm layer for after.
About Afon Glaslyn in Nant Gwynant
The Afon Glaslyn begins its journey high on Snowdon in the cold, clear waters of Llyn Glaslyn — the corrie lake at 600 metres on the mountain's eastern face. It descends through Llyn Llydaw (the miners' lake below the Miners' Track), drops steeply to Llyn Gwynant in the valley, and continues south through Nant Gwynant past Llyn Dinas before reaching Beddgelert and eventually the sea at Porthmadog. The river's entire journey from mountain corrie to coast is through some of the finest scenery in Wales.
The wild swimming pools near Pont Bethania are where the river is most accessible and most used. The bridge at Pont Bethania is on the A498 and has a Natural Resources Wales car park adjacent, making this one of the most conveniently reached wild swimming locations in Snowdonia. The pools have clear mountain water, smooth rock margins to enter and exit, and the profile of Snowdon and Crib Goch visible above the valley to the north — a mountain backdrop that few other wild swimming spots in Wales can match.
The valley as a whole has more to offer than just the river. Llyn Gwynant — 1 mile to the north — is a large, beautiful lake with a campsite and is itself one of the most celebrated wild swimming lakes in Snowdonia. Llyn Dinas to the south is smaller, less visited and very peaceful. The Watkin Path to Snowdon starts from Pont Bethania. Beddgelert village, with its cafés, pubs and the legend of Gelert the faithful hound, is 3 miles south.
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
The most popular wild swimming pools on the Afon Glaslyn are near Pont Bethania (LL55 4NQ) — the bridge in the middle of Nant Gwynant where the A498 crosses the river. There are accessible pools immediately upstream and downstream of the bridge, reachable from the NRW car park nearby. Further upstream towards Llyn Gwynant and Llyn Dinas, the river has additional pools. The valley path (part of the Watkin Path approach to Snowdon) follows the river and gives access to multiple spots.
Nant Gwynant is the valley south of Snowdon and Moel Siabod, running from Beddgelert in the south to the Pen-y-Gwryd junction in the north, through which the Afon Glaslyn flows. It is one of the most beautiful valleys in Snowdonia — the combination of the river, the lakes (Llyn Gwynant and Llyn Dinas), the woodland and the mountains above creates a landscape of exceptional quality. The A498 through the valley is one of the classic Snowdonia scenic drives.
The Afon Glaslyn generally has excellent water quality — it drains directly from Snowdon's high-altitude corrie lakes and flows through relatively undeveloped upland country. As with all river swimming, water quality can vary after heavy rainfall (agricultural runoff) and the river runs fast in spate conditions when swimming is not appropriate. Calm, clear conditions — typically after a dry period in summer — give the best conditions. Never swim in the main current during or after heavy rain.
Nant Gwynant is richly concentrated with attractions. <span lang="cy">Llyn Gwynant</span> (1 mile north) is a classic wild swimming lake; <span lang="cy">Llyn Dinas</span> (1 mile south towards Beddgelert) is peaceful and beautiful. The Watkin Path to Snowdon starts near Pont Bethania, giving walkers a route to the summit from the valley. Beddgelert village (3 miles south) has cafés, pubs and the legend of Gelert the hound. The Welsh Highland Railway passes through Beddgelert.
The best wild swimming conditions on the Afon Glaslyn are from June to September, when water temperatures are highest (though still cold by lowland standards) and the river is more likely to be at lower, safer levels. The valley can be busy in summer — arrive early to find parking at Pont Bethania. In autumn and winter the river runs high and fast and is not suitable for swimming, though the valley scenery is dramatic in all seasons.