Deep in the hills to the north of Dinas Mawddwy two contrasting valleys, Cwm Hengwm and Cwm Cywarch, provide gateways to the Aran range. Today’s walk explores the two valleys and the area between them, enjoying spectacular and ever-changing views. We start by climbing up through Cwm Hengwm on a gently rising path raking across the grassy hillside. Emerging at the head of the valley, the climb continues over Drysgol (745m) to the RAF memorial cairn on Drws Bach. Rather than continuing to the main Aran ridge, we now head across to join a path along a fence line, descending gradually to reach the top of Cwm Cywarch. Here we turn to head into the valley and follow a steep, rocky path down beside a small stream. The gradient eventually eases leaving us with a short stroll back to the start.