Explore the exhilarating majesty and mystique of Southeast Alaska with National Geographic's Alaska's Inside Passage Destination Map. The Inside Passage is a meandering waterway formed by a myriad of islands that lie between the North Pacific Ocean and the quieter waters along the coast. At its heart is the Tongass National Forest, the largest national forest in the United States which at a staggering 16.8 million acres contains 19 designated wilderness areas and the Admiralty Island and Misty Fiords National Monuments.