"LLANFAIR-IS-GAER, (or Bryn Llanfair) a parish in the hundred of Is-Gorfai, county Carnarvon, 2 miles N.E. of Carnarvon, its post town, and 7 from Bangor. It is situated on the shore of the Menai Strait, and includes the township of Brynffynon and port of Dinorwig. The Roman general, Agricola, crossed over to Anglesey at this point. Copper is obtained here, and slate is shipped at the above port. The living is a perpetual curacy in the diocese of Bangor, value £77, in the patronage of the bishop. The church, dedicated to St. Mary, is close to the water's edge. This place takes the suffix to its name-Gaer, signifying a fort or place for defence-from the old Roman camp. The seats are Plas Llanfair, and on the opposite bank, Plas Llanidand, the estate of Lord Boston."
"BRYNFFYNON, a village in the parish of Llanfair-is-Gaer, hundred of Is-Gorfai, in the county of Carnarvon, North Wales, 2 miles to the N.E. of Carnarvon. It is seated on the Menai Straits, near the Bangor and Carnarvon branch railway."
"DINORWIC, (or Dinorwig, Port), in the parish of Llanfair-is-Gaer, in the county of Carnarvon, 2½ miles N.E. of Carnarvon. It is situated on the Menai Straits. The slate quarry, 9 miles by railway from the Straits, employs 1,000 men."
"PORT-DINORWIG, a small harbour in the parish of Llanfair-is-Gaer, county Carnarvon, 2 miles N.E. of Carnarvon. It is a station on the Bangor and Carnarvon branch of the Chester and Holyhead railway. It is situated in the Menai Straits, and has a small pier, where slates are shipped from the neighbouring quarries."