The Llŷn Peninsula (Welsh:Penrhyn Llŷn or Pen Llŷn, Welsh pronunciation: [ɬɨːn]) extends 30 miles (50 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. Much of the eastern part of the peninsula, around Criccieth, may be regarded as part of Eifionydd rather than Llŷn, although the boundary is somewhat vague. The area of Llŷn is about 400 km (150 sq miles), and its population is at least 20,000.