Sarn Helen
Sarn Helen refers to several stretches of Roman road in Wales. The route, which follows a meandering course through central Wales, connects Aberconwy in the north with Carmarthen in the west. Despite its length, academic debate continues as to the precise course of the Roman road. Many sections are now used by the modern road network while other parts are still traceable. However, there are sizeable stretches that have been lost and are unidentifiable.
The route is named after Saint Elen of Caernarfon, a Celtic saint, whose story is told in The Dream of Macsen Wledig, part of the Mabinogion. She is said to have ordered the construction of roads in Wales during the late 4th century.
Route
Aberconwy–Carmarthen
In the north the route is believed to follow the western bank of the river Conwy from Canovium, a fort at Caerhun, passing through Trefriw, then leading on to Betws-y-Coed, with a branch leading to Caer Llugwy near Capel Curig. The route then passed through Dolwyddelan, running through the Cwm Penamnen valley and past the higher parts of Cwm Penmachno. The route then leads on past Llan Ffestiniog to the Roman fort of Tomen y Mur, near Trawsfynydd before continuing south towards Dolgellau.South of Dolgellau the route passes over Waen Llefenni into Cwm yr Hengae to Aberllefenni. Part of the narrow-gauge Corris Railway between Aberllefenni and Maespoeth Junction may run along the line of the Sarn. A minor road running along the east bank of the Afon Dulas near Esgairgeiliog, Powys might be Roman in origin. Although potentially the Roman road remained on the west bank of the Dulas between Corris and Ffridd Gate.
Sarn Helen might have crossed the Afon Dyfi at a ford or ferry near Cefn Caer, a small Roman fort at Pennal in southern Gwynedd.
In Ceredigion part of a B-road at Bronant is Roman, and six miles south is a long stretch through the hamlet of Stag's Head. The road is identifiable at Llanio, where there was a small Roman fort named Bremia. The route then heads southeast towards the Dolaucothi Gold Mines near Pumsaint, Carmarthenshire, before passing the substantial Roman fort of Luentinum before finally reaching its historical end at Alabum. The Roman encampment was on Llanfair Hill. In the 12th century, the Normans reused part of the site and its earthworks to build the mediaeval church of St Mary's Church, Llanfair-ar-y-bryn. The fort stood at the junction of Roman roads, linking the Dolaucothi gold mines to Moridunum and Y Gaer near Brecon.