ancient Mona
County (pop., 2001: 66,828), Wales.
It encompasses Anglesey island, the largest island in England and Wales (276 sq mi [715 sq km]), and Holy Island. Anglesey island is known for its ancient history and its prehistoric and Celtic remains. By 100 BC the Celts had colonized the island, which became a famous Druid centre and later a stronghold of resistance to the Romans. It finally fell to Edward I . Tourism is now an important part of the county's economy.