Cwm Eigiau from Carnedd Llewellyn
At the summit of Carnedd Llewellyn, we were in brilliant pure sunshine, above the layer of blue haze that stretched around the horizon. Walking back, we looked down into Cwm Eigiau, from where we had struggled up the long grassy slope. There, it had seemed a clear sunny day, with no indication of being at the bottom of a layer of polluted air.