Underground Ruins

The Underground Ruins is an area located within the Clay Tunnel. The legendary giants, Regirock, Regice, and Registeel, can all be found here, depending on which Key is active. Originally, the rooms of the ruins only provide hints on to how to open Regirock's chamber (which hint is available depends on if "the sun" or "the moon" is out), but fulfilling the conditions will change the great door into the entrance of Regirock's chamber and all other chambers activated by Keys. Regirock can be found in the Rock Peak Chamber, which is opened when the player presses the A-button after walking 6 steps down and then 9 steps right, from the center of the panel just before the great door.