NPRNTitleType Of SiteArchivesImagesNPRN752TitleGarreg-Ddu Dam, Elan Valley Water Scheme;Carreg Ddu Viaduct and Submerged DamType Of SiteDAMArchives60Images40NPRN32527TitleElan Aqueduct: Foel Valve Tower; Garreg-Ddu Reservoir Tower, Foel TunnelType Of SiteVALVE TOWERArchives19Images14