This 7600-acre wildlife refuge, occupying the uninhabited North Monomoy and South Monomoy Islands, is a haven for shorebirds and seabirds. Nearly 300 species nest here and 10 times that number pass through on migrations. It's one of the most important ornithological stops on the entire Atlantic seaboard. Monomoy Island Excursions offers a Monomoy wildlife boat tour.