Black Smoke city
According to the little information still existent about this world Ancient history, the black smoke was always there, rising over the the whole forest located at the south of the Sea of Rock and rising up, forever. Most civilizations where to far from it to see it Some early civilizations would attribute it different meanings, usually related to the weather or distant deities. More often than not, it was a reason of worry for them. Smoke was, for all of them, related to unwanted fires and that meant danger. With time, they all got used to see it. As some of them developed combustion energy sources, the idea of it being the result of some huge city was considered by many, and a couple of expeditions were arranged by those who looked for cooperation. As far as we know, no one actually saw the city, even if a few got to hear some descriptions about it. They found military camps or observation towers, and there are unconfirmed stories about meetings and treaties with the rulers of the city who called themselves "representantes". Some have records of those meetings going wrong, while others had no details on when or how the relations were broken. Either way, the last mention of them is from 4th Ka BD, and more than a millennium before the earliest reference on the smoke dissipating. After that, those who still care to think about it, thought that the city had fallen, probably due to their own contamination or lost the battle against the dangerous entities that populated the forest. There are still stories though, and well maintained paths that seem to confirm them.
Out of reachFor some reason, even the most skilled percipients are unable to give any detailed information about the people that were supposed to live there (though some of them had confirmed a couple of the stories about the meetings with them), and no kind of ink takes in the Auburn Folios when the topic is this legendary city. The path, always in great conditions, lead to nowhere. Traslation magic always take you to the edge of the forest. Of course, the forest has always been both mysterious and treacherous, but there is still reason enough to think that the maybe this settlement is neither abandoned nor lost, but hidden.