The word Trewern is Welsh, formed from the words "tre" meaning town and "gwern" meaning alder (a tree), thus town of the alder or, more likely, alders.
Although only a small village in terms of population, there is a primary school, Ysgol Gynradd Buttington Trewern, with pupils travelling from miles around. Also, the school has a public playing area for children to play at. Trewern also has many other sites, such as an extinct volcano in form of Moel y Golfa, Cefn y Castell and Breidden Hill