Plum Island is a small barrier island just off the extreme northeast coast of Massachusetts and is part of Newbury, Newburyport, Rowley, and Ipswich. The residential part is mainly Newbury and Newburyport; you can tell which part is which by the color of the street signs; green for Newbury and blue for Newburyport. The island is named for the hundreds of beach-plum bushes growing everywhere. (The harvest is unpredictable from year to year, but the small plums make great jam or jelly when you can get enough of them to bother with.) The clickable plum at the bottom of the page is from a bush on Old Point Road. It's about 2/3 actual size (depending on your monitor).
The island is separated - barely - from the mainland by the Parker River; the northern tip is at the mouth of the Merrimac River. Most of Plum Island (the southern part) is the Parker River National Wildlife Refuge, but the northern portion is densely settled with both year-round and seasonal residents. The architecture is an almost unbelievable jumble of old beach cottages, comfortable saltboxes, standard residential homes, intriguing modest little treasures, and oceanfront trophy houses.
Virtually the entire oceanfront is beautiful public beach, although much of it is accessible only by foot. There are boardwalks in the Refuge that take you through the dunes and out onto the beach; these are great for sightseeing or birdwatching or just calming down.
The inland side faces spectacular tidal marshes (especially at sunset) with a continually changing population of birds ranging from plovers, redwing blackbirds and kildeer to egrets, gulls, great blue herons, and occasional snowy owls. You can see the marsh hawk on her hunting trip most mornings before about 8:00. (Janet Egan keeps a more-or-less current list of her sightings at http://world.std.com/~jegan/plumbirdlist.html.)