In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Nash like this:
NASH, a parish, with a small village, in Newport district, Monmouth; on the coast of Bristol channel, at theleft side of the mouth of the river Usk, 3 miles S W of Llanwern r. station, and 3½ S S E of Newport. Post-town, Newport, Monmouth. Acres, 3, 563; of which825 are water. Real property, £4, 792; of which £10 are in fisheries. Pop., 284. Houses, 54. The property is divided among a few. The living is a vicarage in the diocese of Llandaff. Value, £80. Patron, Eton College. The church is pretty good. Charities, £30.
GB Historical GIS / University of Portsmouth, History of Nash, in Newport and Monmouthshire | Map and description, A Vision of Britain through Time.
Date accessed: 30th March 2017
Click here for more detailed advice on finding places within A Vision of Britain through Time , and maybe some references to other places called " Nash ".