Cregennan Lakes (Llynnau Cregennen) are two natural lakes on the northern slopes of Cadair Idris in southern Eryri (Snowdonia), sitting around 800 feet above sea level with sweeping views over the Mawddach Estuary toward Barmouth. Owned and managed by the National Trust, they’re a genuinely quiet, often-overlooked spot compared to the more crowded honeypots elsewhere in the National Park — you can drive right to the water’s edge, and on all but the busiest days, you’ll have long stretches of the shoreline to yourself.

History of Cregennan Lakes

A Glacial Landscape Beneath Cadair Idris

The two lakes sit on volcanic rock shaped by glacial activity during the last ice age, and the wider site is designated a Site of Special Scientific Interest (SSSI) in recognition of its geological and ecological significance. Glacial fossils and rare lichens can genuinely be found across the surrounding heathland if you know where to look, and the larger lake, around 11 hectares with a small wooded island, and the smaller, roughly 5-hectare lake nearby, sit within a landscape that’s remained recognisably wild and largely unaltered for centuries, even as farming has shaped the ground immediately around them.

Working Hill Farms

The National Trust manages two sheep and cattle farms spread across the heath and woodland surrounding the lakes, continuing a tradition of upland grazing that stretches back generations in this part of Wales. Small drystone enclosures dotted across the landscape mark where livestock once sheltered from the weather, a quiet, functional counterpoint to the more dramatic mountain scenery around them, and a reminder that this is still a genuinely working landscape rather than a purely ornamental one.

The Legend of Cadair Idris

The mountain the lakes sit beneath carries one of Wales’s better-known pieces of folklore: Cadair Idris, meaning “the chair of Idris,” is said to take its name from a giant who once used the mountain as his seat. A further, widely repeated legend holds that anyone who spends a full night alone on the mountain’s summit will wake as either a madman or a poet — or, in some tellings, not wake at all. It’s folklore rather than documented history, but a genuinely enduring one, still told to visitors gazing up at the peak from the shores of Cregennan below.

National Trust Stewardship

Cregennan has been in National Trust care for decades, part of a wider portfolio of South Snowdonia land that also includes the ancient oak woodland at Dolmelynllyn. The Trust’s management here balances public access and traditional hill farming against the site’s SSSI conservation status — exactly the tension that explains several of the specific rules covering the lakes today, including the restriction on swimming covered below.

Visiting Cregennan Lakes: Practical Information

Getting There

Cregennan Lakes sit around 5 miles from Dolgellau, reached via a genuinely narrow, winding stretch of country lanes climbing up from the Mawddach Estuary — part of the appeal, but worth being prepared for if you’re not used to single-track Welsh mountain roads. The grid reference is SH657143 for anyone navigating by map rather than satnav.

Parking and Facilities

A National Trust car park sits right beside the larger lake, with basic toilet facilities nearby — there’s no café, shop, or visitor centre on site, so bring what you need with you. This is one of the few genuine beauty spots in the area where you can park within a few steps of the water rather than needing a long walk in first.

Walking Around the Lakes

The simplest option is crossing the road from the car park to reach the shoreline of the larger lake directly, where the distinctive peak of Pared y Cefn-Hir rises on one side and a rustic boathouse and small wooded island sit within view. The smaller second lake is reached by a short walk across farmland, usually grazed by sheep, making spring a particularly good time to visit if lambs add to the appeal for younger walkers. Neither route is long or especially demanding by Eryri standards, though the ground is genuinely uneven, steep and boggy in places, with narrow gates and stiles to navigate.

Pared y Cefn Hir Viewpoint

For a more ambitious walk, the climb to the top of Pared y Cefn Hir — itself a nationally important geological site — rewards the effort with panoramic views over the surrounding mountains and the Mawddach Estuary beyond, genuinely one of the better viewpoints in this part of southern Eryri without the crowds of Cadair Idris’s own summit paths.

Can You Swim in Cregennan Lakes?

Genuinely important to know before you pack a wetsuit: wild swimming and paddleboarding are prohibited at Cregennan Lakes, specifically to protect the rare species the site’s SSSI status was designated to safeguard. This is a real, actively enforced rule rather than a vague suggestion, and it’s worth knowing in advance given how many other Eryri lakes do welcome open-water swimmers — Cregennan is a genuine exception, not the norm.

Fishing at Cregennan Lakes

Unlike swimming, fishing is genuinely encouraged here: both lakes are run as a fly-only trout fishery, stocked with blue and rainbow trout, with fishing permitted from 8am. Permits are available from Ffridd Boedel Farm, Arthog, Gwynedd, LL39 1LJ (telephone 01341 250426), with notably affordable rates for younger anglers — under-14s can fish from as little as £5. It’s a genuinely welcoming setup for families as much as serious anglers, provided everyone sticks to fly fishing rules.

Terrain and Accessibility

Per the National Trust’s own description, the countryside here includes uneven, steep, rocky and boggy terrain in places, along with narrow gates and stiles — genuinely not a fully accessible site for wheelchairs or standard pushchairs, despite the ease of parking right beside the larger lake. The immediate shoreline near the car park is the most manageable stretch; anything beyond that should be treated as proper countryside walking rather than a level park path.

Wildlife to Look Out For

The site’s SSSI status reflects a genuinely rich range of species: mossy saxifrage, marsh St John’s wort and fen bedstraw among the rarer plants, the marsh fritillary butterfly, and the wheatear, a small migratory bird that arrives each spring and is often first noticed by the flash of its white rump in flight before it’s properly spotted.

Nearby: Cadair Idris and Arthog Falls

Cregennan makes a natural add-on to a wider Cadair Idris trip, with the mountain’s own visitor centre and the popular Minffordd Path to its summit both a short drive away. A waymarked route also connects Cregennan to Arthog Falls and the Mawddach Estuary further downhill, for anyone wanting to extend a single visit into a longer, more varied walk through this quieter corner of southern Eryri.

Frequently Asked Questions

Can you swim in Cregennan Lakes?

No, wild swimming and paddleboarding are prohibited to protect the rare species the site’s Site of Special Scientific Interest status was designated to safeguard.

Where are Cregennan Lakes?

On the northern slopes of Cadair Idris in southern Eryri (Snowdonia), around 5 miles from Dolgellau, at grid reference SH657143.

Can you fish at Cregennan Lakes?

Yes, both lakes are run as a fly-only trout fishery. Permits are available from Ffridd Boedel Farm in Arthog, with reduced rates for anglers under 14.

How do you get to Cregennan Lakes?

By car via a narrow, winding stretch of country lanes climbing from the Mawddach Estuary, around 5 miles from Dolgellau, with a National Trust car park right beside the larger lake.

What is the legend of Cadair Idris?

The mountain is said to be named after a giant, Idris, who used it as a seat. A well-known legend also holds that anyone who spends a night alone on its summit wakes as either a madman or a poet.

Is Cregennan Lakes accessible for wheelchairs or pushchairs?

Not fully. The National Trust describes the terrain as uneven, steep, rocky and boggy in places, with narrow gates and stiles, though the immediate shoreline near the car park is the most manageable stretch.

Cregennan pairs naturally with a wider trip into southern Eryri, including Pen y Fan further south in the Bannau Brycheiniog. Browse the full Wales guides collection for more of the country’s landmarks and landscapes.