A Welsh wonderland of slate and feral goats

Llanberis, Snowdonia In a clearing, a black-headed beast with horns as magnificent as any fairytale faun, is munching grass next to an old red-painted winding house

The glug-glug of bubbles on the surface is a sign of divers in the depths. I watch their dark shapes rippling slowly in the emerald water for a while, before taking a slippery slate staircase winding up through the still autumnal oak woodland surrounding the flooded Vivian quarry.

In a clearing lit briefly by November sun, a brown-coated, blacked-headed beast with horns as magnificent as any fairytale faun, is munching grass next to an old red-painted winding house. It is a scene of storybook strangeness. The horned head turns slowly, fixing me briefly with a pair of yellow eyes, then returns indifferently to its business.