Puffin Island is an uninhabited island off the eastern tip of Anglesey, Wales. It was formerly known as Priestholm in English. A hermitage was established here around the 6th century, and there are remains of a 12th-century monastery on the island. The island is also a Special Protection Area for wildlife.

Anglesey is an island off the north-west coast of Wales. It forms the bulk of the county known as the Isle of Anglesey, which also includes Holy Island and some islets and skerries. The county borders Gwynedd across the Menai Strait to the southeast, and is otherwise surrounded by the Irish Sea. Holyhead is the largest town, and the administrative centre is Llangefni. The county is part of the preserved county of Gwynedd.