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.
The main towns and villages of Inishowen are:
Inishowen is a peninsula of 884.33 square kilometres (218,523 acres), situated in the northernmost part of the island of Ireland. It is bordered to the north by the Atlantic Ocean, to the east by Lough Foyle, and to the west by Lough Swilly. It is joined at the south to the rest of the island and is mostly in County Donegal in the Republic of Ireland. The south-eastern part of the peninsula lies in County Londonderry, Northern Ireland, having been transferred from Donegal at the behest of the London companies as part of the Plantation of Ulster in the early 17th century. The peninsula is separated from the rest of Northern Ireland by the River Foyle.