At the northern edge of town on Route 3, this museum is on the campus of the College of the Atlantic (www.coa.edu; [tel] 207/288-5015), a school founded in 1969 with a strong emphasis on environmental education. The museum occupies the national park’s original HQ (who knew?), and features exhibits that focus on interactions among island residents, from the two-legged to the four-legged, finny, and furry. Check the museum’s summer program: in summer, you just might stumble across a nature walk, art project, or scavenger hunt. At the very least, swing by to see the 13-foot, 1,800-pound skull of a fin whale that sits outside, a campus landmark.