Hafren Forest is the outdoor heart of a Llanidloes stop. Trails run beside the young River Severn, past cascades and through conifers, with longer routes climbing toward the source of the river on the slopes of Pumlumon.
Choose the shorter cascade walks if the weather is poor, or take the Source of the Severn Trail when you want a proper half-day in the hills. The forest is quiet rather than spectacular in a postcard way, but it gives Llanidloes a real mountain edge.