Llyn Dwythwch

Llyn Dwythwch is a small mountain lake above Llanberis in Gwynedd, north Wales. It sits in Cwm Dwythwch, a glacial hollow on the north-western flank of the Snowdon massif, inside Snowdonia (Eryri) National Park. Hikers on the busy Llanberis Path barely see it, which makes it a quiet target for anyone avoiding the crowds.

How do you get to Llyn Dwythwch?

The approach starts at the back of Llanberis, where a gravel track climbs towards the cwm. Most ordinary cars manage it, though four-wheel drive helps in bad weather. Parking is just below the lake, next to a ruined building beside the track. From there it is roughly a 10-minute walk up a gentle slope to the shore.

What will you see?

At around 12 acres, the lake is fairly large by local standards. It is framed by the slopes of Moel Eilio, Foel Gron and Foel Goch. It suits a short outing or a picnic, but weather turns quickly up here, so bring a waterproof layer.

Can you fish here?

Yes. The Seiont, Gwyrfai and Llyfni Fishing Society manages the water. It holds plenty of wild brown trout, mostly 6 to 12 inches, with the odd bigger fish. Any fishing method is allowed. The margins are shallow, so waders are handy, and the trout tend to rise best on overcast, unsettled days. Day tickets are sold through Fishing Passport and society outlets, and a single ticket of about 20 pounds covers all of the society's waters.

Is there a walking route through the cwm?

The Cwm Dwythwch Round is a loop from Llanberis of about 7.5 miles (12 km) with close to 2,500 ft (760 m) of ascent. It crosses three summits: Moel Eilio (726 m), Foel Gron (629 m) and Foel Goch (605 m), then drops around the cwm and rejoins the Llanberis Path near the Pen Ceunant cafe. It is a demanding ridge walk, with Snowdon's summit in view for much of the way.

When should you visit?

Dry days from late spring to early autumn are best, when the track and paths are in good shape. Anglers often prefer cloudy weather. In winter, slopes can ice over and visibility drops.

Frequently asked questions

Can I drive to Llyn Dwythwch?

A gravel track leads to the parking area below the lake and is usually fine for ordinary cars. After heavy rain, a 4x4 is the safer choice.

How far is the walk from the car park?

About 10 minutes on a gentle uphill path.

Do I need a licence to fish?

You need a day ticket, available through Fishing Passport or the fishing society's outlets.

Is this the lake from the dragon legend?

No. The dragon legend belongs to Dinas Emrys in Nant Gwynant, not to this lake above Llanberis.