You've seen those trees before, In a dream. You remember now it was a nightmare, and you were wandering in a strange forest, where the trees were twisted and wept blood. These giants stretched far above you, blotting out the sun and sky. You remember running from a voice that spoke of dark magic and "The Broken Place". This is not the forgotten land, for it was never known.
The painting of the Cities of Jade, metropolises to the north, is unremarkable. You remember that they transmuted mud brick to jade with magic. This is not the forgotten land, it's quite known.