There's a ladder on the wall on the opposite of the side with the stone couch. Have Ico climb the ladder and call Yorda when he reaches the top. Take her hand and walk through the doorway. Go to the end of the pathway and pull the switch, which opens the next set of small circles farther to the right. Have Ico light his staff from the nearby torch, take Yorda's hand, and jump off the ledge to the right down to the floor below with Yorda in tow. She'll protest mildly but be alright. Move to the nearest small circle and light it as before, then head over to the other one and do likewise. If the fire at the end of the tip is extinguished in the meantime, just head back to the other small circle and relight it. Doing so opens the larger circle and frees the sword on the other side, that you saw when they entered the arena.

Take her hand and head through the door. To the right as they enter the room with the stone couch, is the sword that was released and fell to the floor. Go over to it and pick it up, which will cause Ico to drop the staff as only one weapon can be carried at a time. As this is accomplished, a large metal grate rises and surrounds the two of them on three sides. Note the two ropes attached to wheels atop the two metal platforms on either side of the three circles just opened. Climb up onto either metal platform and cut the rope. When the same has been accomplished with the other one, the metal gate will drop back down. Head up the staircase on the opposite side of the stone couch and jump and cut the rope at the top to release the door below. Now head back down and save your game.