PORT-DINORWIG, a port (small), in the parish of LLANVAIRISGAER, hundred of ISGORVAI, county of CARNARVON, NORTH WALES, ai miles (N.N.E.) from Carnarvon: the population is returned with the parish. This place, anciently called "Aber Pwll," is situated on the Menai strait, and has a commodious harbour, accessible at high water to vessels of a hundred tons' burthen. It forms a convenient shipping-place for the produce of the slate mines in the parish of Liandeiniolen, from which a railroad, seven miles in length, extending from the quarries to this place, was constructed in 1824, for the conveyance of the slates, of which not less than twenty thousand tons are annually shipped. The harbour, which has been recently enlarged, is capable of accommodating thirty vessels, which may lie here in safety while waiting for their freight, and the quay has been greatly improved.