Bardsey Island (bärd`sē), Welsh Ynys Enlli, 0.7 sq mi (1.8 sq km), Gwynedd, Wales, off the SW tip of the Lleyn Peninsula. The small island, which rises to 548 ft (167 m), is separated from the mainland by the 2-mi-wide (3.2-km) Bardsey Sound. It is the site of a lighthouse. Known as the island of 20,000 saints because of its history as a place of holy burial (legend says King Arthur was buried there), it was settled in the 5th and 6th cent. by monks and was major pilgrimage destination in the Middle Ages. Following the dissolution of the monasteries by Henry VIII, the island fell into disrepair. Now a nature reserve with a small year-round population, Bardsey also has several prehisoric sites.