For the white rabbit, walk down stream from the fortune teller on the same side of the river; you will see the rabbit in a cutscene before you hit the rocks with the iron ore deposit. It will lead you north and a bit west, and should keep stopping until you get close.
Return to the fortune teller, and she will have another prediction (someone you will run into to the far south;
on a bridge near where you found the bandit's axe.
Most of Broken Valley will be inaccessible after you get the battle tower. However, you will still be able to return to the quarry and rescue the people from the level 27 Black Ring members and enter the mine (the tops of towers will be ok, as well).
There is a warning when you reach a point in the battle tower where you will no longer be able to go back. Until then you can return to Broken Valley from Sentinal Island.