Or, where is the ancient island of the Sun Warriors? Because call me old-fashioned, but if they were really the original masters of Firebending and lived on an island that big, I wouldn't just have it as a random dot in the middle of the ocean. And there's the complaint that it's noticeable if it's a big place, I have doubts that the Fire Nation would actually try to take it, especially considering it's all in creepy booby-trapped ruins. Zuko, for one, seemed to know where it was.