Fallen Renin is a strange phenomenon. It is another city, similar in many ways, that seems to exist in the same place as Renin. Indeed, there are similar buildings, streets, geographical features, etc. These are not identical, however; Fallen Renin seems to be older than Renin, and is largely deserted. Those who know of it theorize that it is the city at some unknown time in the future, after a terrible catastrophe has all but destroyed the place. Wayfarers speak of the eternally burning Barrowdale fire, and rumours of a lost elven forest are widespread. Less widespread, but still extant, are the tales of the Black Fountain.
Most inhabitants of Renin don’t know about Fallen Renin. Only the Wayfarers have the ability to find their way between the two cities, and they tend to keep their own counsel about things.