Llanfyllin is a small market town, community and also selecting ward in a sparsely-populated location in Montgomeryshire, Powys, Wales. Llanfyllin's population in 2011 was 1,532, of whom 34.1% might talk Welsh. Llanfyllin indicates church or church (llan) of St Myllin ('m' frequently mutates to 'f' in Welsh). The town lies in the valley of the River Cain near the Berwyn Mountains in Montgomeryshire, 14 miles (23 kilometres) southwest of Oswestry as well as 15 miles (24 km) from Montgomery. The River Cain is joined by the little River Abel in Llanfyllin (most likely named after Cain and also Abel in the Bible), and meanders via the valley, streaming right into the River Vyrnwy at Llansantffraid. The community exists between Shrewsbury and also Bala, for a long period of time the vital market communities in this field of Wales and also the Welsh borders. At close-by Bodyddon there is proof of an early British settlement. Llanfyllin might be the "Mediolanum amongst the Ordovices" described in Ptolemy's Location (c.? ad 150), although others argue for Meifod or Caersws. The town is known for its divine well, Fynnon Coed y Llan. The well is dedicated to Saint Myllin, that is reputed to have baptised individuals below in the sixth century. The parish church is also committed to Saint Myllin. There is a tradition that Saint Myllin is the Irish bishop, Saint Mo Ling (also called Moling Luachra) (614-- 697). Nevertheless, this is uncertain. There is no document of Mo Ling taking a trip to Wales, and there is a tradition that Myllin is buried under the altar of Llanfyllin church whereas Mo Ling is thought to have actually been buried at his monastery in Ireland.