You must first get Waillord and Relicanth. Then, go to Pacifidlog City. Go left into the currents. You will see a square in the water. Dive down then go into the cave. Get to the end of the cave. You will see Braille on the wall. While in front of the Braille, dive up. You will be in a cave. Go to the end of the wall and use Dig to enter the next room. You must have Waillord first in your party and Relicanth last. Then, read the Braille. The ground will shake and the caves will now be open. One is in the desert and the other is in the water in near Deleford Town.