The last thing Leras does before dying is appear to Elend and point to the Northeast. He also did that the first time he met Elend. If you trace the two lines from their approximate locations, you end up in the far right corner of the Terris mountains.
Hence the question: what was in the Terris Dominance that Preservation was pointing to? And why was it so important that Leras used the last of his strength to try and tell Elend about it?