The falls are born in the Berwyn mountains. The Afon Disgynfa is, at first, not unlike the other streams formed by rain leaking out of the moors.
But the Disgynfa doesn’t survive its sudden plummet over a sheer shelf of volcanic rock, a landform tough enough to have escaped the scouring of the glaciers in the last ice age.Transformed by the falls, the waters continue their journey as the Afon Rhaeadr.
The big freeze
Spray from the cataract nurtures mosses and ferns. Around them, protected from sheep in a walled enclosure, beeches, birches, oaks and pines thrive. From a distance, the wooded gorge and falls resemble an almost Tyrolean scene, which in winter is usually a fecund refuge for squirrels, woodpeckers and finches sheltering from the Berwyns’ icy blasts.
But on occasion, the falls freeze. Green becomes white. Like vintage lampshades, icicles fringe the ledges, encapsulating fern fronds and grasses. The water freezes incrementally, gradually expanding and building, petrifying the scour pools, sculpting holes and shapes and bridges to rival the rock’s own architecture, till the murmur and babble of water is silenced. But the ice has its own language, communicated through creaks and pops and moans and tinkles. Few people see them like this – one or two gutsy ice climbers, and walkers more than motorists. The road from Llanrhaeadr-ym-Mochnant is rarely closed but often slippery.
Out on the hills
Above the falls, the Berwyns, bare and blasted, hold snow for longer than anywhere else in Wales. It’s easy up there to envisage the Ice Age in which the falls were created and the valleys gouged. Easier to imagine the frozen tundra of frigid winds, stunted shrubs, horses, Arctic foxes, lemmings and steppe pika that replaced the glaciers, than the forest which replaced it. The trees were destroyed by humans and supplanted by blanket bog and heath, both now actively conserved. Rogue saplings are removed and the land intensively sheep-grazed to nurture the heather moorland and game birds it supports. The moorland also sustains golden plover, ring ouzels and hen harriers, though their populations are declining.
If you do brave the conditions, you may hear, above the ice cracking beneath your feet and the brutal howl of wind in your ears, the chuckle of cowering red grouse. Or perhaps you’ll see a black grouse, lifting up and away from the frozen tussocks in short whirring flight, like a mountain puffin.