Sometimes, on the borders of sleep, I remember the walk down from Hay Bluff to the Vale of Ewyas. Along the Brecon escarpments. Across the watershed into Nant Bwch, a ravine with a stream far below. Past a group of buildings where, in Victorian times, there was a monastic retreat, and where in the 1920s an artistic commune flourished for a time. If I have not drifted off, I pause at the church at Capel-y-Ffin, with its stumpy chimney like the tail of a perching wren; and before turning down the valley towards the ruins of Llanthony Priory I lift my drowsy mind’s eye to the ‘Vision’ farm, high on the fern-covered flank of a hill in the heart of the Black Mountains. In my mind’s ear there is the rushing sound of the River Honddu, the voice of the Vale of Ewyas.