It is located behind Silver Falls on Sophian Island. This location is divided into areas with very noticeable differences, including a cave, mines and the ruins. The mines contain Claydol, which teleport players back to the beginning of the area they entered, similar to the Dusclops in the Noir Forest. However, these Claydol can see all around them, thus not allowing players to capture them. There is a Dusknoir lithograph covering up a room in the ruins. The player can break the lithograph and gain access to the cave by beating the Dusknoir in the final Dark Temple past mission.
Another part of this area leads to a part outside, where players can heal, save and even use Ranger Signs. Flying away from this area, however, requires players to begin from the entrance of the entire Oblivia Ruins. Players cannot fly directly to this area.
At the end of the ruins is a wall that shows a prophecy that involves the player and the villains of the game, as well as several of the Legendary Pokémon encountered in the game. The floor in the same room shows the status of the Legendary birds. The yellow one on the left is black when the player first arrives at the ruins. The door in the said room leads to a room, where several villains of the game drink tea together.
At the end of the main run through to the end, the player will face Purple Eyes for the first time and his Steelhead army. The next run through introduces the Societea as the game's main antagonists. The Sky Fortress is stored in a lake behind the ruins.