In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Llanddewi Aber Arth like this:
LLANDDEWI-ABERARTH, a village and a parish in Aberayron district, Cardigan. The village stands on the coast, at the mouth of the river Arth, 2 miles NE of Aberayron, and 13 NW of Lampeter r. station; and has fairs on 5 July and 11 Dec. The parish contains also part of the town of Aberayron, which has a postoffice under Carmarthen. Acres, 3,595; of which 75 are water. Real property, £2,244. Pop. in 1851,1,284; in 1861,1,463. Houses, 353. The property is not much divided. Remains of a fortified camp, called CastellCadwgan, are near the shore. ...
The Aberayron workhouse is here; and, at the census of 1861, had 10 inmates. The living is a p. curacy in the diocese of St. David's. Value, £310. Patron, the Bishop of St. David's. The church is dedicated to St. David, is aucient, and was recently rebuilt. The chapelry of St. Alban is a separate charge, and is under the patronage of the proprietors of Ty-Glyn estate. There is an endowed school with £7 a year. See ABERAYRoN.
A Vision of Britain through Time includes a large library of local statistics for administrative units. For the best overall sense of how the area containing Llanddewi Aber Arth has changed, please see our redistricted information for the modern district of Ceredigion. More detailed statistical data are available under Units and statistics, which includes both administrative units covering Llanddewi Aber Arth and units named after it.
GB Historical GIS / University of Portsmouth, History of Llanddewi Aber Arth, in Ceredigion and Cardiganshire | Map and description, A Vision of Britain through Time.
Date accessed: 28th June 2016
Click here for more detailed advice on finding places within A Vision of Britain through Time, and maybe some references to other places called "Llanddewi Aber Arth".