Llyn Brenig is a reservoir located on Denbigh Moors in North Wales. The artificial lake, which was constructed between 1973 and 1976, was created by building an embankment dam across the Afon Brenig valley. It lies at 1,200 ft (370 m) above sea level on the border between the counties of Conwy and Denbighshire. It is used to manage the flow in the River Dee as part of the River Dee regulation system.

Conwy County Borough is a county borough in the north of Wales. It borders Gwynedd to the west and south and Denbighshire to the east. The largest settlement is Colwyn Bay, and Conwy is the administrative centre.