High Quality Content by WIKIPEDIA articles! Lundy is the largest island in the Bristol Channel, lying 12 miles (19 km) off the coast of Devon, England, approximately one third of the distance across the channel between England and Wales. It measures about 3 by 0.75 miles (4.8 by 1.2 km) at its widest. Lundy gives its name to a British sea area and is one of the islands of England.