Acadia National Park, located mostly on Mt. Desert Island in coastal Maine, features dramatic views of the Atlantic Ocean atop jagged, maritime cliffs. Once called Lafayette National Park, Acadia is the oldest national park east of the Mississippi River. Many visitors to Acadia stay up all night to see the sunrise on Cadillac Mountain. It is said to be the first place in the United States to see the sunrise each day. Nearly two million people visit Acadia National Park each year.