The forecast threatened us with the hottest day of the year – in September! – so it was with floppy hats, water pump and lashings of sunscreen that we set off up into the hills to investigate the state of the aquatic plants, not recorded since 1976, at Llyn Carw, the hidden lake which sits high above the Elan reservoirs atop the ridge facing Drygarn Fawr.  Fortunately for the Intrepid Five, a light but delightful breeze came and went, and in the afternoon some very welcome clouds came over so the temperature on the ground never went above 26C.  But it was distinctly steamy, especially for a long and sometimes steep ascent.

The hot week had materially dried out the boggier bits on the track, but the lake itself was still brimming (it’s hard to tell how deep it may be) and the dragonflies and damselflies were busily hunting and mating all around the edges, while a solitary small frog croaked musically among the rushes at one end.  After a welcome break for lunch, we started the circuit, successful avoiding the spots where apparently solid ground proves to be only an inlet between tussocks.  Floating bur-reed and bog pondweed were easily visible floating on the surface and, after much hunting and disappointment, we did find a our prime objective, a quillwort (precise species still to be verified at the time of writing). In the marshy ground beside the lake was a satisfyingly large patch of round-leaved sundews and cranberries in among the mosses.

Refilling our water supplies from a stream at the top (not the infant Rhiwnant, spilling out from the still lake waters) we trudged a narrow path across interminable molinia to the top of the Rhiwnant’s valley to look at the mine ruins with their lunar spoil heaps, and followed the beautiful little river down its long sequence of waterfalls and swirling pools to the main valley below.

Spurning the sturdy but oddly positioned bridge (it may be intended to help those whose objective is to visit all of the valley’s mines? it certainly doesn’t help walkers aiming to get back to the Claerwen road) we splashed and paddled across the ford and ambled back along the track to the cars – heat-drained and, truth be told, somewhat travel-stained, but hugely satisfied with our day on the hills.