Wikipedia
Rhiwaedog
Rhiwaedog is the name of an ancient estate in North Wales, located in the Penllyn forest near Bala, Gwynedd. It gives its name today to two hills, Rhiwaedog-is-Afon and Rhiwaedog-uwch-Afon, meaning "Rhiwaedog below the river" and "Rhiwaedog above the river" respectively. There is also the ancient manor house Plas Rhiwaedog, from which Rhirid Flaidd (also known as Rhirid ap Gwrgenau) ( fl. 1160) ruled his demesne.