In the Pokémon games, the specific cave known for finding rare candies is the "Sapphire Cave," commonly referred to as the "Cave of Origin" in Pokémon Omega Ruby and Alpha Sapphire. Players can also find rare candies in various locations throughout the Hoenn region, such as the Sea Mauville and the Victory Road. Exploring these areas thoroughly often yields hidden items, including rare candies.
Catch zigagoons and phanpies they sometimes have it
In granite cave.
You have to find him in a cave, id say the elite four cave
In sootopolis.
in the littleroot cave
get the HM dive and dive down and you'll find a cave entrance
Go inside shoal cave.
In Dewford at the cave, Not hard to find.
in the cave where aaron are found
you will find him underwater in a cave
You find Kyogre in The Cave of Origin in Sootopolis city
you have to go to caves theres like hundreds of them in caves hope this works to you because I found a lot in my sapphire game!