Gwynedd Archaeological Trust

Ymddiriedolaeth Archaeolegol Gwynedd

01248 352535

The Menai Straits 2000 years of history

A small tidal rock at the low water mark on the shoreline south-west of the headland of Cerrig y Borth, between the suspension bridge and Stepenson's Railway bridge.

At the point where the track (part of the later Belgian Prom) meets the beach there survives two stone piers, or walls, marked quays on a marine chart of 1853, perpendicular to the high water mark, 50m apart. A lime kiln had been inserted into the steeply rising ground at the back of the beach. It was certainly in place in the 1850s and may have been built during the construction phase of the suspension bridge. The stone quay walls may also date to around this period. After the demise of the ferry the space between these walls became a popular bathing place.

Immediately to the north west, above the level of the beach, there existed an ‘ancient enclosure’ of 2/3 of an acre in the hands of the Marquis of Anglesey. The Enclosure Award plan (1815), Rennie’s map (1810) and the survey of Telford's Resident Engineer, William Provis (1820s) all show a building, or buildings and a small garden within this enclosure. These structures probably represent the old tenements of the ferrymen at Carreg yr Halen.

The Carreg yr Halen Ferry plied a route to a landing place at Treborth Mill directly across the Straits. The journey is 300m at high tide slack. This is an area of dangerous tides and strong currents and the timing of the crossing is important. High tide slack occurs 1hour and 40 minutes before high tide at this point.

Treborth Mill is the location of a former water mill, fed from the fast stream that cascades down the almost precipitous bank on the southern shore at this point. The site is now occupied by a private house with a landing stage at the high water line