Reconnoitring Wales’ Celtic rainforest: a walk in the woods of Coed Felenrhyd and Coed Llennyrch

© Kerry Walker

Distance: 4.25km (loop) or 7.25km (with 3km out-and-back extension).

The road north from Dolgellau is among Snowdonia’s best: a surprisingly straight, wide A-road ushering traffic south to north across the National Park with little to see, ostensibly, but dense belts of forest until you hit the coast around Portmeirion. Which is perfect, because forests and lingering in ostensibly-little-to-see areas are what we are here to do. The most famous manifestation of woods hereabouts are Coed-y-Brenin, where the UK’s first and foremost dedicated mountain bike trail network careens through the conifers. But today we stay on the way north that skirts the shores of Llyn Trawsfynydd, Wales’ largest body of water by surface area, and at the village of Gellilydan turn onto the sort of road we feel much more content upon – the meandering into-the-wilds singletrack that will deliver us to our destination.

Already on this two-mile serpent of a byway, which feels like ten because of the requisite gate to open and close and the wheels-brushing-either-verge ponderousness with which we are required to proceed, the woods are thickening around us. But there is less of Coed-y-Brenin’s dense, inky spruce and far more dispersed deciduous thrusting up out of the ruffled heathland here. Where firs do preside, it is atop a forest floor that bursts with ferns and grasses rather than the spartan, dark, needle-strewn ground-space common to many of Britain’s closely-packed conifer plantations. They feel more open, these woods, and they feel old. Mists-of-time ancient, in fact: fragments of the arboreal coverage here harks back an incredible 10,000 years.

For a site that secretes some of the UK’s only remnants of rainforest, Coed Felenrhyd and adjoining Coed Llennyrch announce themselves with little ceremony. No sign directs you here. We park where our lane drops to meet the road from road from Maentwrog on the edge of the wide, flat Afon Dwyryd valley in a dim lay-by besides a hydroelectric power plant. Once woodlands like that now surrounding us would have tumbled in abundance off Snowdonia’s western flanks but few tracts survive. They were a valuable source of timber for shipbuilding in the 19th and early 20th centuries, when no one thought preserving such habitats was necessary. Those that remain are the great unknowns of Snowdonia: without the thrills of peaks or coast, perhaps, but with a dank, timeless, Tolkien-like allure.

There are several other regions of rainforest in Scotland, Northern England and, under the auspices of Celtic Rainforests Wales, four separate Welsh sites. ‘Rainforest’ being a catchy moniker, of course. Britain employs many monikers like this to sell its destinations: the ‘English Riviera’ (Devon), the ‘Naples of the North’ (Llandudno and Morecambe) – as if these places could only be portrayed if other, long-established continental holiday spots are used as the descriptors. The Welsh rainforest, though, is not a punchy phrase to ramp up the tourism (and sure enough there is none here) but a term to describe particularly moist broadleaf forests that receive high rainfall and, as a result, have exceptional biodiversity. Whilst ‘rainforest’ may be associated with the Amazon Basin, that is just the tropical variety. There is also the temperate rainforest, of which these woodlands stand out as one of Britain’s best examples.

West of the bridge through which gushes the Afon Prysor, the scurrying river that endows Coed Felenrhyd and Coed Llennyrch with their special character, a noticeboard that has seen better days reveals a little more. The gloom-heavy gorge we stand beside, enclosed almost completely by its precipitous slopes, has become a warm, watery, mist-enveloped microclimate, allowing certain species including horseshoe bats, mosses, lichens and liverworts to thrive to much greater extent than they ever could elsewhere. Also preserved here are sessile oakwoods that trace their roots to the end of the last Ice Age: a fecund legacy from early Neolithic Britain.

© Kerry Walker

The route through the rainforest

We begin our exploration from bottom to top, taking the upper path immediately after the noticeboard rather than the lower alongside the river (anti-clockwise is the best way to do it, although we did not know that at the time!) The circular walk indicated seems straightforward but because this is Snowdonia, it is not: long enough and steep enough to be called a hike rather than a stroll.

The images of the woodland online compete with each other to showcase the greenest camera frame possible and thus embellish the fact they pertain to a piece of writing on rainforests but, coming on an overcast end-of-the-season Saturday, canopy foliage was already mostly fallen for the year, allowing greater visibility across the valley but depriving us, perhaps, of that perfect, lush rainforest shot.

Even so, it is an immediately, intensely verdant path that soon gives us the primordial feel we seek. Branches and boughs drip in full-flowing beards of lichen. Trunks are blanketed by moss several metres up from the base. Ferns and auburn bracken render the forest floor a living, breathing, bristling thing: often too tangled to stray off the path and into. A waterfall, white and furious, charges across our trail. Venerable broadleaf forest still refreshingly dominates over spruce. It begins to rain, a light persistent mizzle which at least has us satisfied we are authentically experiencing one of the 200 way-above-the-average wet days the area gets in the year compared to its North Wales surrounds. Wetter than the average North Wales day is very wet indeed and so we become, but gradually, a steadily encroaching all-over dampness in the rainforest way, rather than a sudden and utter soaking.

Our path is muddy but always defined, picking up the moss-blanketed boundary wall of the former Oakeley estate after a while and ascending to a broad metalled track at a small gate. On this track we turn left, with two houses unexpectedly appearing ahead of us like an apparition of already-forgotten civilisation. Our trail does not dally long on the broader thoroughfare, diving to the left behind the far wall of the lower house and now proceeding on a mid-sized, rough forest track that passes a tumbledown cottage further along on the left. We soon descend to a fast-flowing tributary of the Afon Prysor at a dividing of the ways.

© Kerry Walker

A dividing of the ways and Coed Llennrych

Straight on through the (sometimes dangerously) rushing tributary, the path enters Coed Llennyrch, a spread of enchanting broadleaf woods that elevates you up on mostly tiny, enchanting paths, across a spell of open heath and to the shore of Llyn Trawsfynydd reservoir. This way is an out-and-back one, but provides you with a complete ecosystem transition: the almost estuarine Afon Dwyryd, the rainforest and then Wales’ largest lake. The lakeshore is stark but spectacular. The story goes that when the reservoir was constructed in 1928, locals were less worried about the fact waters would be harnessed to supply a hydro-electric power station (and later a nuclear power station) and more concerned about loss of rights of way. As a result, Llyn Trawsfynydd is well served by trackways around its titanic waterfront, including the firm, metalled route winding along this part of the shoreline, which can be followed a fair distance should you wish to explore further. This is well worth doing: vistas are expansive enough to conjure images of snaking Scottish sea lochs, with this particular gangly arm of the water becoming a passage out to open ocean, and the Snowdonia summits behind it distant islands.

The waterfall walk

We re-cross the tributary back to the path junction and carry on down its north-western bank, down alongside this divide between Coed Felenrhyd and Coed Llennrych to meet the wider, wilder Afon Prysor again just before the most beautiful section of the walk at the frothing plume of Rhaeadr Du. This is a breathtaking, as-if-from-nowhere waterfall that plunges the river from upper, lighter woods to lower, darker, denser ones. It plays sorcery with the light even on a flat, grey day: a grand finale, if ever there was one. We pause in the silence the moment warrants, revelling in our own, foliage-draped little portion of The Lost World, for we have not seen a soul these last two hours to share all this with.

The steepness of the gorge’s sides increases all the while now, and with it the intense majesty of those veteran oakwoods: gradients thankfully made harvesting timber too tough back in the day, and replanting with standard forestry equally so, so there has been little tampering with the ecosystem here for millennia besides the path we now take. The route skips down the easier-going side of the river (the one you are on, you will be pleased to know!) with a newfound glee as if the waterfall has got it all excited.

And this final stage, helter-skeltering you back down to the murky ravine bottom, is the route’s finest.

Turn after turn of untouched-by-time trees…

One thing we are acutely aware of. This is not just any old wintry walk in the woods. We are seeing a side to Snowdonia most miss. Yes, it is a rare pocket of British rainforest. But the words that keep coming back to us as we gaze at the gorge and therefore, we think, are the most apt to end this article with, are from Coleridge’s Kubla Khan:

‘…But oh! That deep romantic chasm which slanted

Down the green hill athwart a cedarn cover!

A savage place!… holy and enchanted…’

NEXT ON THE JOURNEY: From Coed Felenrhyd it is 44 miles northwest to Anglesey’s ultra-romantic coastal step-back-in-time Ynys Llanddwyn

At a glance…

How to get there: Coming the way we did, from Dolgellau, exit the A487 shortly after its join with the A470 at Gellilydan. The turn-off forks immediately; turn left and follow the minor lane 2.5 miles through the village, farmland, woods and valley down to the A496 besides the hydroelectric power plant. The lay-by you park in is just to the right of the junction. Otherwise, access the same lay-by (on the right, coming like this) by coming off the Gellilydan-Penrhyndeudraeth stretch of the A487 at Maentwrog and continuing through the village on the A496 for one mile.

Parking: Just the lay-by. Space for three or four vehicles.

Refreshments: Maentwrog, one mile from your start point, has (although you would scarcely think it given its diminutive size) a pub. We haven’t been there so cannot vouch for it, but it looks lovely.

Best time to visit: Spring and summer bring the foliage to show the rainforest off in its full glory, but it makes a great winter walk too and trees largely shelter hikers from those 200-odd rainy days!