Abergwyngregyn (Welsh: [abɛrɡwɨnˈɡrɛɡɨn]) is a village and community of historical note in Gwynedd, a county and principal area in Wales.

[1] Abergwyngregyn, generally shortened to Aber, is a settlement of great antiquity and pre-conquest importance on the north coast of Gwynedd.

Protected to the east by the headland of Penmaenmawr, and at its rear by Snowdonia, it controlled the ancient crossing point of the Lafan Sands to Anglesey.

A pre-Roman defensive enclosure, Maes y Gaer, which rises above Pen y Bryn on the eastern side of the valley, has far reaching views over Irish Sea with the Isle of Man visible on a clear day.

The Roman road from Chester (Deva), linking the forts of Canovium (later name Conovium) and Segontium, crossed the river at this point.

E. S. Armitage, in The Early Norman Castles of the British Isles, suggested that it might have been constructed by Hugh d'Avranches, Earl of Chester.

The word mŵd in early Welsh means 'vault' or 'arched area', and though there are traces of a ditch on the south side, no further defensive features have been identified.

[3] Other similar mounds, such as the one on which the Pillar of Eliseg near Llangollen stands, or the one at Scone in Scotland, have been found especially in northern and western Britain.

It appears to be the remains of a high status building from the 14th century, possibly contemporary with the last independent princes of Wales or with the early decades after the Conquest.

Pen y Bryn is a manor house, recorded from the Jacobean period and with earlier lower stonework, on a promontory some two hundred yards to the east of the village centre.

[citation needed] The valley provides the access to one of Wales's great waterfalls, the Aber Falls as the Afon Goch falls precipitously, some 120 feet (37 m) over a sill of igneous rock into a marshy area where it is joined by two tributaries; the enlarged stream, Afon Rhaeadr Fawr, heads towards the Menai Strait and the sea.

Aber is the coastal crossing point for the ancient drovers and later Roman road that led across the Lafan Sands to Anglesey.

The Roman road from Chester crossed the river Conwy south of Tal-y-Cafn, connected with the fort at Conovium Caerhun by a short branch, then led up via Rowen and Bwlch-y-Ddeufaen, the Pass of the Two Stones, as an engineered overlay on top of the earlier British trackway, into Snowdonia.

By the shore, a hide has been erected on the edge of the Menai Strait, providing clear views of the seabirds on the Lafan sands.

As a young man, Sir Peter Scott used Twr Llywelyn, part of Pen y Bryn, as a place to position his telescope, to watch the birds flying in off the Irish sea.

The Carneddau have a notable range of glacial and periglacial features that have been studied by geologists, including Charles Darwin, for well over a century, and plays a key role not only into research into landforms, but also into climate change and vegetation history.

Like most of the United Kingdom, Aber has an oceanic climate with warm summers, cool winters, few extremes of temperature and moderate rain all year round.