It rises at Cwm y Saeson, and flows east past Cefn Llech to Sychnant, where it is joined by the Full Brook.
Here it turns north past the ford at Rhyd Myheryn at Glanyrafon, receiving the Rhydyclwydau Brook on the right bank.
The old track bed of the Mid-Wales Railway follows the course of the Dulas from this point, through the valley towards Llanidloes railway station.
The Dulas continues flowing north-west past the village of Tylwch beyond which it forms a narrow rocky gorge, which has been used by whitewater kayakers, although fallen trees across the gorge are a reported hazard.
At Rhos-y-pentref, where the river is measured, it is joined by Nant Gynwydd, and is crossed by the A470 road.
Turning north once more, the river passes Upper Glandulas where it meets its last tributary the Afon Brochan, before joining the Severn to the south-west of Llandiloes at Felindre.
It rises at Cwm y Saeson, and flows east past Cefn Llech to Sychnant, where it is joined by the Full Brook. Here it turns north past the ford at Rhyd Myheryn at Glanyrafon, receiving the Rhydyclwydau Brook on the right bank. The old track bed of the Mid-Wales Railway follows the course of the Dulas from this point, through the valley towards Llanidloes railway station. The Dulas continues flowing north-west past the village of Tylwch beyond which it forms a narrow rocky gorge, which has been used by whitewater kayakers, although fallen trees across the gorge are a reported hazard. At Rhos-y-pentref, where the river is measured, it is joined by Nant Gynwydd, and is crossed by the A470 road. Turning north once more, the river passes Upper Glandulas where it meets its last tributary the Afon Brochan, before joining the Severn to the south-west of Llandiloes at Felindre.
Afon Dulas, Llanidloes