Naoshima is one of Japan’s best destinations for art lovers. Previously, this island in the Seto Inland Sea was a copper-smelting hub, but it suffered a population decline as younger generations left for the mainland. However, in the early 1990s, the land was reenvisioned as an open-air museum. Now the island is home to 15 galleries and creative outdoor spaces, and art is the common thread through it all, from the local bathhouse to high-end hotels.