I found the entrance to the Cavern of the Incarnate. The mountain where it's located seem to be the needle, though I'm not sure. The skin of the pearl is supposed to be a brighter area in the rock, that will lead me into the cave (I'm assuming it's a hidden door), but I just can't find it... no brighter areas, and even though I circle that mountain, just pumping spacebar in case it's hidden, it just won't work. Has anyone else got this far?

If you want directions, go to the ahemmusa camp and ask about the needle and skin of the pearl. They'll give you directions. I couldn't see a bright rock personally but did find the cave :)

Just enter the farthest northeast foyada (that begins at sea and is a dead end - look at your map) and follow it till you reach the cave entrance. Or was it the foyada that is just next to it.. Oh well can't really remember now :D