Here are the two contradicting points:

East of the lake
Quote Originally Posted by Erik
The aether of the area is in an extremely chaotic state. I had long thought this to be a result of the Battle of Silvertear Skies, but have learned that this is not the case! The disturbances I have observed do not all derive from a single source. Beyond the imperceptible aether emitted by the Keeper of the Lake, there are even stronger aetherial waves coming from deep below the earth to the east.

I have studied these waves in great detail, and discovered that they can be used to reconstruct an image of their source. And I believe their source is a tower! An enormous, vast, gigantic, underground tower! Do you not see? <sigh> Of course you don't... It could only be the lost tomb of Xandes I, ”€the first emperor of Allag of whom I spoke mere moments ago. But wait, there it more to tell! You see, it is impossible that a normal building, however large, could release so much ethereal energy. An immense crystal on the other hand, ”€that most certainly could. Putting these observations together, I had no choice but to conclude that the ancients' seemingly fanciful references to the tomb being wrought of crystal were not so fanciful after all!
Southwest of the lake, near where the former falls would be.
Quote Originally Posted by Cid Garlond
Aye, it happened. The Crypt of Xandes I lies in the depths of Silvertear Falls. What you saw took place there, when van Darnus finally tracked me down. I thought myself as good as dead.