Eglwys Nunydd
Neath Port Talbot, United Kingdom
The Eglwys Nunydd is a 260-acre (110 ha) supply reservoir in Margam, Wales. It was originally constructed in 1963 to provide cooling water for the cold rolling mills at the nearby Port Talbot steelworks.
Reservoir data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).