Rock Peak Ruins

The Rock Peak Ruins is a special cave in the middle of Route 228 in Pokémon Platinum. It is located down a slope of sand near the north gate. It is called the Rock Peak Ruins because it is the home of Regirock, the Rock Peak Pokémon. Normally, if the player enters the cave, it is empty. However, after entering the Hall of Fame, if the player has a fateful encounter Regigigas in their party, there will be a 7-dot pattern on the floor and a statue on the back wall.