Dwygyfylchi Parish

Most of the town lies on a small coastal plain about 2 miles in length and half a mile deep facing Conwy Bay and the Irish Sea to the north. The bay is sheltered by the south-east tip of Anglesey and Ynys Seiriol (Puffin Island) to the north-west and the limestone headland of Pen-y-Gogarth (the Great Orme) to the north-east. The sea is shallow here between Traeth Lafan and the Conwy estuary. The beach is extensive, consisting of smooth pebbles and a wide expanse of sand. Two impressive headlands separate Penmaenmawr from its neighbours. In the west the huge bulk of Penmaenmawr ("Penmaenmawr mountain") lies between the town and neighbouring Llanfairfechan and the wider coastal plain extending to Bangor. To the east the smaller but no less rugged headland of Penmaen-bach divides Penmaenmawr from Morfa Conwy (Conwy Morfa). To the south an arc of hills and uplands extends east to west from the latter to Penmaenmawr, beginning with Yr Allt Wen above Dwygyfylchi, Bwlch Sychnant (the old road crosses this pass to Conwy), Pen-Sychnant, the rounded hill of Foel Lys, Gwddw Glas (Green Gorge), Bryn Derwydd and the head of Cwm Graiglwyd and finally Penmaenmawr itself. Penmaenmawr is very wooded and also has a fair number of fields. The coastal plain itself is nearly divided by Trwyn-yr-Wylfa, which also marks the boundary between Pant-yr-afon and Penmaenan in the west and the "Hen Bentra'" or "Old Village" of Dwygyfylchi and Capelulo in the east. Finally two small rivers flow through the area. The first, Afon Pabwyr, runs down from wooded Cwm Graiglwyd then under the town centre, Pant-yr-Afon, to the beach; the second and larger, Afon Gyrrach, runs for about 4 miles from the northern slopes of Tal-y-Fan to the sea near Penmaenbach, passing through Nant Ddaear-y-llwynog (The Fairy Glen) and the "Old Village".
 

Prehistory
The uplands above the towns have a wealth of prehistoric remains, including the site of prehistoric axe factories on the western slopes of Cwm Graiglwyd near the top of Penmaenmawr. This was once one of the most important stone axe manufacturing sites in Europe. There is evidence that axes from Graiglwyd were exported widely 5,000 years ago, examples having been found as far a field as Cornwall and south-east England. The nearby Meini Hirion, known in English as Druid's Circle, is a prehistoric stone circle, one of the finest in Wales. A prehistoric trackway from Bwlch-y-ddeufaen to Conwy runs by the circle. The summit of Penmaenmawr, from which the town takes its name, was 1,500 feet above sea-level until reduced by modern quarrying. The summit area was crowned by Braich-y-Dinas, one of the largest Iron Age hill-forts in Wales and indeed Europe, comparable with Tre'r Ceiri near Trefor on the Llyn peninsula; unfortunately nothing remains today, the last remnants having being obliterated in the 1920s.

Medieval and Early Modern Period

In the Age of the Saints tradition has it that the 5th or 6th century Saint Seiriol, after whom Ynys Seiriol (also known as Puffin Island or Priestholme) is named, had a hermit's cell in Cwm Graiglwyd. A declivity, Clipyn Seiriol, above the modern road tunnel through Penmaenmawr, also bears his name, as does the modern church of St Seiriol's near the town centre. Seiriol was a son of Helig ap Glannog, a Prince who lived at Llys Helig, covered by the sea, and which has given rise to the legend of the drowned Palace. The older church of St Gwynin's in Dwygyfylchi is the parish church today. Penmaenmawr is also associated with St Ulo, Capelulo being at the foot of Sychnant and reputedly the site of an early medieval chapel.

From the early Middle Ages onwards the parish has been part of Arllechwedd Uchaf, and this ancient Welsh cwmwd (English commote), which together with neighbouring Arllechwedd Isaf makes up the cantref (hundred) of Arllechwedd, is still used by the church as an administrative unit today.