Acadia National Park is about 90 minutes southeast of Bangor — close enough for a day trip, though most visitors prefer at least one overnight in Bar Harbor. The park covers most of Mount Desert Island and includes Cadillac Mountain, at 1,530 feet the highest point on the East Coast north of Rio de Janeiro, with a summit road that brings you to the top for sunrise or sunset views across the island-dotted Atlantic.
The park has excellent hiking on a network of trails built largely in the early 20th century, plus 45 miles of carriage roads — crushed-gravel paths closed to motor vehicles — that wind through the forests and over stone bridges. The village of Bar Harbor, just outside the park, is well supplied with restaurants and accommodation. In peak summer (July-August) the park gets very crowded; aim for early morning starts or consider visiting in September when the crowds thin and the foliage begins to turn.