Due west of the 1Z map starting point, there's a ruin next to the swamp that is under water. Your sovereign can't get to it to search it. I tried using the raise land spell to raise the ruin to the surface, but the spell could not be used on that tile. You can see from the following screen shot that I was able to raise the land around the ruin, but the ruin itself remained under a lake that I could not remove, and my sovereign still could not move onto that tile.
