y late start meant that the sun was already much further west than I had hoped. The light had moved on from the eastern slopes, and deep shadows lay across the shoulder of Cadair Idris, with the summit outlined in sharp relief against the deep blue of a flawless sky. I took the lane that runs gently uphill between stolid banks of mossy stone towards a band of low woodland. As I walked, I tried to roughly calculate the mass of the stonework I passed – and before reaching the top of the rise, less than a mile distant, I had accounted for several hundred tonnes. Most of this would have not been brought far, just prised from the ground and heaped to form boundaries in an attempt to improve the rough grazing either side of the lane. Today, ewes and their small upland lambs grazed unconcernedly among clumps of soft rush as I wandered past in the spring sunshine. Even in this landscape of rock, and little else, the scale of the effort needed to build these walls is impressive. Yet trees, growing unchecked from the field margin, have heaved the massive blocks aside in places – leaving parts of the structure in a precarious state. Beyond the crest of the hill, the lane dipped between patches of pleasantly unkempt woodland. Small streams, rock bedded, flowed only gently due to the lack of rain – and the dry moss and lichen that covered the boulders at the margin formed a crisp, matted carpet. Bramble stems as thick as my thumb hung heavily across the walls, already sprouting tight clumps of leaf at their growing points as they wove insidiously across the landscape. Dropping towards the valley of the Afon Wnion, I found a field gate to lean on while I ate my belated lunch. In the far distance, dimmed slightly by haze, the afternoon sun glinted on the surface of the Mawddach estuary where the river wound tightly between sandbanks and marshes. The heat of the day made it tempting to linger, but time was short and, reluctantly, I began the long descent towards Dolgellau.