Llyn Dulyn (Welsh for 'black lake') is a lake on the edge of the Carneddau range of mountains in Snowdonia, North Wales. The lake is 33 acres (130,000 m2)
Afon Dulyn (English : River Dulyn) is the outflow from Llyn Dulyn, a lake in the Carneddau mountains in north-west Wales. It is a tributary of the river
Foel-fras, mountains in the Carneddau mountain range. It is a tributary of Afon Dulyn, itself is a tributary of the river Conwy. A third is a stream flowing north-west
Dyflin, modern Icelandic Dyflinn and modern Manx Divlyn as well as Welsh Dulyn and Breton Dulenn. Other localities in Ireland also bear the name Duibhlinn
Welsh for "bridge") in the name probably refers to the bridge over the Afon Dulyn, a tributary of the nearby River Conwy, which runs through the village.