Tucked away on Australia’s idyllic Whitsunday Island, this 4-mile beach owes its silky, talcum-powder sand to 99.8-percent pure silica grains. Backed by lush acacia forest and a shore that fades into crystal cerulean waters, the setting both recalls and transcends island clichés. Strict visitation limits enforced by the Great Barrier Reef Marine Park Authority ensure it stays that way.
