well they are secret bases but you need to teach one of ur Pokemon secret power(tm43), and u can get it in slateport city at the open market!(In Pokemon Sapphire).
Those are secret bases to create one use the move secret power.
hit a wall
A little square in the wall, look on certain routes to find these.
Use dive near that one huge rock RIGHT UP AGAINST THE WALL AND IN THE CENTER There should be an entrance underneath.
It is because you have awoken the three Regis:Regirock,Regice,and Registeel.
Those are secret bases to create one use the move secret power.
hit a wall
Run in to a wall and you get a fire type pikachu
Those are secret bases. Just like those big trees. You need Secret Power to activate it though.
A little square in the wall, look on certain routes to find these.
Use dive near that one huge rock RIGHT UP AGAINST THE WALL AND IN THE CENTER There should be an entrance underneath.
have relicanth first wailord last (or other way around) in line up then use dig and back wall.
It is because you have awoken the three Regis:Regirock,Regice,and Registeel.
You must use the HM move, Dive, on the chain dark spots on Route 128. Then, go to the southern most area and there should be a opening in the wall.
its in the team aqua/team magma (for ruby) hideout near lilycove. the first two are electrode and the second two(the ones near the wall) is a master ball and a nugget.
To open the small indent on the wall in "Emerald," you typically need to interact with it using an item or completing a specific task related to the game's mechanics. Look for clues in your surroundings or nearby objects that might unlock or trigger the indent. Often, these indents require a specific action, like solving a puzzle or finding a key item. Check for any hints within the game's environment that suggest how to proceed.
go to mossdeep city. after use surf and go until the water is deep. use dive then swim until you see a hole in a wall and go in