Sand spits and coconut palms hold sway in the outer barrier islands, but Chuuk’s glory lies in its vast, shallow lagoon. This 64-kilometer-wide (40-mile-wide) sanctuary attracted the Imperial Japanese Navy, which based its fleet here during part of World War II . . . until the U.S. attacked (with a ferocity and destructive power often compared to Pearl Harbor). The battle littered the seafloor with wreckage: an evocative and haunting spectacle that now attracts divers from around the world. But Micronesia’s easternmost state has much to offer beyond this kaleidoscopic underwater world. It consists of 10 atolls, 19 high volcanic islands and 225 low-lying coralline islets. Fringed by mangroves, the bigger landmasses contain lush tangles of trees including mango, banana, coconut and breadfruit. Many locals still live close to the land: fishing, subsistence gardening and hunting for octopus with flashlights on the reefs at night. Visitors should be prepared to slip into these easy rhythms; Chuuk is wonderful, but not a bright-lights-big-city sort of place.