(Acrylic painting) Inishowen (Irish: Inis Eoghain, meaning "island of Eoghan") is a peninsula in County Donegal, Republic of Ireland. It is the largest peninsula on the island of Ireland. Inishowen is a picturesque location with a rich history. The peninsula includes Ireland's most northerly point, Malin Head, along with Lagg sand dunes, some of the highest in Europe. The Grianan of Aileach, a ringfort that served as the royal seat of the over-kingdom of Ailech, stands at the entrance to the peninsula.