Explore details about location Lon y Dderwen. Lon y Dderwen is a location situated within the Rhiwbina alongside other areas such as Waun Fawr Road, Tŷ'n y Cae Grove, Heol Tŷ'n Y Cae. Additionally, some smaller parts of Lon y Dderwen include specific areas like Bryntirion, Clos Mabon, Heol y Coed adding to the diversity of its landscape.