Meaning
This flag stands for Tristan da Cunha, an extremely remote volcanic island group in the South Atlantic, part of a territory that also includes Saint Helena and Ascension.
Its only settlement, Edinburgh of the Seven Seas, is reached by a long sea voyage, so the emoji mostly appears in remote-island trivia, travel dreams and penguin posts, with 🌋 or 🐧. “Bucket list: the island you can only reach by boat 🇹🇦🌋”