Welcome to Acadia National Park on Maine"s rocky, scenic coast. The 49,075-acre park covers about half of Mount Desert Island, smaller nearby islands, and a section on the mainland. The oldest national park east of the Mississippi River and the only one in Maine, Acadia packs a lot of geographical variety into its relatively small size. You"ll find miles of craggy coastline like the shore in our homepage image, woodlands, wetlands, and mountains. The park"s Cadillac Mountain is the highest point along the North Atlantic seaboard and a great spot to take in the sunrise.