First Cave

• When you reach the first stone panel, open your pack and use an escape rope. This causes the stone panel to open so you can enter the chamber where you can collect energy and heal powders, as well as oran and pecha berries. This also unlocks the "A" through "J" Unown Pokemon, which you can now catch to add to the Unown report, given to you to fill out by a scientist researching the Ruins of Alph.
  
  

Second Cave

• To reach the second cave, have a Pokemon in your party who knows how to surf so you can get across a small pond to go to the south end of the ruins. In the cave, examining the stone panel tells you that you need to use flash. Have a Pokemon who knows flash use the ability to open the secret room, which contains an energy root, heal powder, moon stone and sitrus berry, and to unlock Unown "R" through "V."
  
  

Third Cave

• To find the third cave with the stone panel, travel through the Union Cave in the Ruins of Alph. You have to battle trainers and use surf to cross ponds. When you reach the cave, read the stone panel, which indicates that you need to have the Pokemon Ho-oh equipped in your party. Having one unlocks the door to the secret room, which has charcoal, leppa berry, life orb and revival herb, and unlocks Unown "W" through "Z."
  
  

Fourth Cave

• Travel through Union Cave again, taking a different path to find the fourth Ruin of Alph cave. When you get to the stone panel in the ruin, read the message, which indicates that you need to use a water stone here. Get a water stone from Fisherman Tully at route 42, by winning first place in the Bug Catching contest or by trading 2,500 points at the Pokeathlon Dome on weekdays. The secret room has a leppa berry, mystic water, star piece and stadust, and unlocks Unown "K" through "Q."