The Isle of Doagh (Irish: Oileán na Dumhcha, meaning “Isle of the Dune” ) is a small peninsula in the north of Inishowen on the north coast of County Donegal . It once was an island. Over time, the channel between Doagh and the mainland silted up and it became joined to the mainland. Nevertheless, the area continued to be referred as the Isle of Doagh or Doagh Island. The area comprises five townlands; Ballymacmoriarty, Carrickabraghy, Carrowreagh, Fegart and Lagacurry. Doagh Island is very near the village of Ballyliffin.