ABSOLUTE AMAMI

My first glimpse of Amami Oshima from the sky is mesmerizing. Clothed in seemingly endless fields of sugarcane, the rolling northeastern end of the island — a rocky curlicue of scalloped coves and golden beaches — is fringed by coral reefs that extend even around the seaside runways of Amami Airport, where my plane from Tokyo touches down three hours after taking off. To the southwest, the bulk of the island stretches away in broads-shouldered mountain ranges thick with subtropical forest. The October air is balmy and bright; the moist breeze carries the tang of salt and soil. It all makes a bewildering contrast to the megacity I call home.

Much of this impossibly green landscape is now part of Japan’s latest UNESCO World Heritage site, which encompasses three other islands in the Ryukyu Archipelago: neighboring Tokunoshima, the northern part of Okinawa, and distant Iriomote, the so-called “Galápagos of Japan.” Together, they harbor an incredible diversity of flora and fauna, including hundreds of types of birds, the country’s largest butterfly, vipers (for what is