After you're turned away at the Gerudo Palace, Dohna suggests you repair smaller rifts to prove yourself. One is northwest of the oasis.

Where to Start the Quest

You can start the quest during A Rift in the Gerudo Desert after you visit Chief Seera in the palace in Gerudo Town. Leave the palace to get a message from Dohna, then talk to Dohna in the Oasis. Then go to the northwest location marked on the map and enter the cave with the fancy door. Talk to the soldier to start the quest.

How to Complete the Quest

Go to the west wall and bind to the large boulder. Pull it away from the wall to reveal a door that was behind it. Go through.

Defeat the moles to learn the Holmill echo. Then bind to the large boulder at the north wall and pull it left or right to reveal a ladder. Go down.

Get on the sand, and stand one square to the right of the leftmost edge of the sand, then create a Holmill there. Go down the hole it creates, and you will reach a treasure chest if you put the Holmill in the correct place. (If you didn't, you can still reach it.) Stand in front of the treasure chest to get a golden egg.

Then make a Holmill on the sand to the right, and go down the hole. Go to the right and climb up the ladder, and defeat the Ignizol on the right.

Go to the right and go up two ladders. If you haven't gotten all the treasures in the left side of this area, go up the left ladder. Otherwise, go up the ladder on the right to continue to the next room.

Create Braziers or Ignizols to light the torches. There will be a cutscene, and the quest will be completed.