2/3 of Acadia National Park sits on Mount Desert Island with over 50+ luxurious trails to hike. The other 1/3 of the park sits on Schoodic Peninsula and Isle au Haut. There are over 140 miles of short, one-way trails. All the trails at Acadia are intended to be day-hikes because backcountry camping is not permitted within the park boundaries.The trails are maintained by a private endowment, Acadia Trails Forever. Most of the trails are well marked with cairns (small, pyramid-like rock piles) and blue blazed painted onto trees and rocks. Mount Desert Island gets over 2+ million visitors each year. The park and island are nearly split in half by a natural, glacially-carved barrier. This is the only fjord on the U.S. Atlantic Coast.
If you are just staying for the day, make sure to drive the 27 mile park loop road down the east coast of Mount Desert Island. As you make your way down the coast, make sure to stop at the overlook, sand beach, Thunder Hole, Otter Point, and Cadillac Mountain. Keep your camera ready at all times.