A town in a county see Wikipedia -> https://en.wikipedia.org/wiki/Carmarthen
Carmarthen (/ˌkɑːrˈmɑːrðən/ kar-mar-dhən; Welsh: Caerfyrddinpronounced [kɑːɨrˈvərðɪn]) is a community in, and the county town of,Carmarthenshire, Wales.
Did not find Caermorthern, Wales, which I assume is a different way to spell the town and county.