After you beat the story line have the friend area sky blue plains (also the friend area Mt. Moonview if you plan on catching Jirachi while you are there) talk to Ekans and answer his mission about Medicham and you'll unlock the cave. You'll have to rescue her first, then you can go back and face Jirachi. It's 99 floors, temporarily resets you to level 1 and will get rid of any money you are carrying. Be prepared!
you have to beat the game first
In the solar cave behind a locked door that you have to unlock with a key
After you beat the game, you yalk to whiscash. He will giv you dive. He then will say "If you lose this, go to solar cave." And........ poof! you hav solar cave!!!!!!!!!
Go to solar cave
Western cave
In solar cave
recruit ho oh
You can get it with a key the unlock a chamber
wish cave has 99 floors including the jirachi fight at the end.
In Pokémon Mystery Dungeon: Blue Rescue Team, you can access the Seafloor Cave by completing a specific story event. After finishing the main storyline and rescuing the Legendary Pokémon, Kyogre, you will receive a letter from a character named Wigglytuff. This will unlock the Seafloor Cave, which you can then access from the beach area. Be prepared for tough battles within the cave, as it contains challenging Pokémon and a variety of floors.
dioxys and it will be in meteor cave
You'll get it after you beat the game.