Does anyone know where the sink plug is?

Pontsticill Reservoir (Welsh: Cronfa Pontsticill) or Taf Fechan Reservoir is a large reservoir on the Taf Fechan lying partly in the county of Powys and partly within the county borough of Merthyr Tydfil in South Wales. It lies within the Brecon Beacons National Park and Fforest Fawr Geopark. The 110 ft high embankment has, since its completion in 1927, been holding back 3400 million gallons of water for supply to industry and population to the south.
en.wikipedia.org/wiki/Pontsticill_Reservoir

Pontsticill is in the Taf Fechan Valley and sited by a bridge over the Taf Fechan river. The term ‘Zululand’ appears on official documents from the late 1870s onwards as a ‘proper’ address in this area. This is because the Upper Neuadd was built during the Zulu war and was originally nicknamed ‘Zulu’.