Llŷn Peninsula extends 30 miles (48 km) into the Irish Sea from north west Wales, south west of the Isle of Anglesey. It is part of the modern county and historic region of Gwynedd. The name is thought to be of Irish origin, and to have the same root – Laigin in Irish – as the word Leinster. The name Llŷn is also sometimes spelled Lleyn, a spelling which is less common today than in the past and is generally considered to be an anglicisation which ignores the phonetic values of Welsh. Much of the eastern part of the peninsula, around Criccieth, is technically part of Eifionydd rather than Llŷn, although the modern boundaries have become somewhat vague.
