In the company of National Geographic writers and photographers, explore islands of preservation set amid some of the most populated areas of the United States. Meet naturalists and rangers, fishermen and fellow travelers. Journey from the fog-drenched cliffs and teeming tide pools of Acadia in Maine to the glistening saw grass of Florida's Everglades. Go underground at Mammouth Cave. Hike through rhododendrons and mountain laurel fora misty morning view of the Great Smokies, then watch autumn tint Blue Ridge hills and hollows. Dive into the crystal-clear waters of Biscayne, Virgin Islands, and Dry Tortugas, one of our newest national parks.