The gurgling water scatters diamonds into the sunlit air. Flat, lush grassy riverbanks suddenly rise upwards to my left and right and the steep valley sides are covered in gorse, bracken, heather and young trees. Over millennia, boulders from the blackened gritstone outcrops have toppled down into the water to be broken up by the seasonal gushing torrents. Several large flat stones jut out over the river and are heated invitingly by the midday sun, while the riverbed is a mosaic of multicoloured pebbles. Several slippery, moss-covered rocks are laid out like stepping-stones to trick the unwary or foolhardy. The map says ‘river’ but my mind says stream: at no point is it more than six feet wide and, where the water slows to a crawl in one of the many tiny natural dams, it cannot be deeper than two or three feet. This place is peaceful and beautiful. The only sounds, other than the constant chatter of the water, are from the creatures that live here: countless chirruping birds and buzzing insects.

We left the car sheltered in a leafy lay-by about 45 minutes ago and now trudge upstream to find a secluded spot. I carry a rucksack containing just a picnic and a blanket. She simply carries herself: elegantly, confidently, purposefully; long, blonde hair bouncing with every step and her firm, lean body sways like the occasional willow that clings to the valley sides. The short, white, flared dress and walking boots are sexily incongruous, and as she crosses the river at a narrow point, striding from rock to rock, I catch glimpses of her delicious tanned thighs.

‘Come on! Keep up! I’m starving. There’s a good looking rock just up there - it’ll make a nice table.’ And there it is, broad and flat, bathed in sunlight, lightly speckled with exploding droplets from the mini waterfall beside it. The water flows slow and deep here. A little pool, created by the ring of rocks we just walked across. Perfect. She sits and takes off her boots and socks and dangles her slender feet in the icy water.

‘God! It’s cold – feels good though.’

I sit beside her, the heat of the rock soaking into my backside, and soon my feet join hers in the stream. It’s painfully cold, but wonderfully invigorating. I decide to share a secret.

‘When I was about fourteen I came here – had to walk back then of course, about six miles before I even got to where we just left the car… summer’s day, just like this… I started with my feet and then suddenly got the urge to dip myself in… had the idea that the waters would keep me young… it felt great! I felt young - re-born even - an’ promised I’d come back every year and do the same. I imagined myself at eighty, looking like a twenty year old and all my friends thinking I’d sold my soul to the devil…or that I had a really old-looking portrait hidden in the attic.’

‘Did you come back? You look