The route forms a full circuit of the central Black Mountain, starting from Mynydd Du Forest Car Park and following the Grwyne Fawr valley before a sustained climb onto the open plateau. From here it crosses high, broad ground to Twmpa (Lord Hereford’s Knob), then continues north over Rhos Dirion.

The return leg follows the ridge south-east before dropping steadily back into the valley, rejoining the river and track system for the final section back to the car park. Most of the walking is on open moorland and wide ridges, with long climbs, few path junctions, and extended high-level sections.

This is a committing circuit with limited shelter, navigational demands in poor visibility, and a clear sense of distance throughout.