Dinas Mawddwy is a village in Gwynedd within the Snowdonia National Park. The village stands amongst the spectacular scenery where the Rivers Cerist and Dyfi meet under the hills of Foel Benddin (543 m) and Foel Dinas (478 m).
Dinas Mawddwy is just to the east of the main A470, and consequently many visitors pass the village by. The village marks the junction of the unclassified road to Llanuwchllyn which climbs up through the mountains to cross Bwlch y Groes at its highest point, the second highest road pass in Wales. This minor road also provides the closest access to the mountain Aran Fawddwy and is the nearest settlement to Craig Cywarch.
Dinas Mawddwy stands at the confluence of three rivers. The Afon Cywarch flows from the mountains to the north and the Afon Cerist flows from the west, both joining the River Dyfi here. The Dyfi flows south to Cemmaes Road where it turns west to head past Machynlleth to the Irish Sea. The mountains to the north are the Aran Fawddwy range of high, rocky peaks. To the south and the west stand the Dyfi Hills, dominated by Maesglase 3 miles (4.8 km) west of the town. Dinas Mawddwy is dominated by Foel Dinas which looms high over the west side of the valley.
Its population in 2011 was roughly 600.
There are thought to be two Iron Age fortifications in the immediate vicinity of Dinas Mawddwy. One is on the top of Moel Benddin, where a low depression forms the supposed site. The second fortification was in C'aer-bryn field, to the south of the Buckley Arms Hotel, that still had stonework in place in the late 18th century.
The Ancient borough of Mawddwy was the only remaining part of the Kingdom of Powys still ruled by members of the native royal family (of Powys Wenwynwyn) after 1309. On the division of the realm in 1293, Mawddwy had been awarded to William de la Pole (of Mawddwy) and his descendants. The ruling family in Mawddwy would expire in the male line in 1414.
Dinas Mawddwy was the seat of the borough of Mawddwy and received its charter in 1394; it retained that status until 1886. The Mayor of Mawddwy had the power to try offenders within the borough and punish them in the stocks, and to grant licences to public houses.
In the 16th century, the Mawddwy area was home to a band of highway robbers and bandits named the ‘Gwylliaid Cochion Mawddwy’ or ‘Gwylliaid y Dugoed’. The Gwylliaid were supposedly the dregs of society, who came to the Dinas Mawddwy area having been exiled from their own areas. Some were hanged and others were exiled from the area forever. Two brothers pleaded to be pardoned by the Baron Owain, and his rejection of the plea enraged the Gwylliaid. They were intent on revenge and one night, while the Baron travelled home from Montgomeryshire, the Gwylliaid set traps on the road and shot arrows at the baron and his company. His body was found with thirty arrows attached to it.
Dinas Mawddwy is just off the A470, the main north-south trunk road in Wales. The nearest railway station is at Machynlleth, from where there is a regular bus service.