From the North Palace, go as far south as you can and then go a little to the right and you should see a cave. Inside this cave is a jar!

Once you get the hammer, exit the cave and break a rock nearby, which will reveal a cave. Guess whats inside? A Jar!

When you are in the maze island, choose the outer L-shaped passageway. One of the road squares here is actually a pit with the third Jar in it!

If you talk to the old lady at the House of Kasuto she will let you in her home. At the back of the house a jar is lying there for you to take.