on sapphire/emerald this one boy gives you the move secret power. use it to make a secret base!
you need a Pokemon that knows secret power use that move to make your secret base
You cannot make a secret base in Pokemon soul silver.
You cannot make a secret base in Pokemon soul silver.
you cant cover the holes in your secret base.
Get the TM secret power teach it to a Pokemon then find either a tree with vines, an indent in the wall or a big bush use secret power on these to create your own secret base.
Go underground.
you can't
in the underground.
In your secret base.
You can't, unless you mean secret base. You have to have a Pokemon with Secret Power. Use Secret Power in front of a tree or an indention in rock.
It is underground
In the Pokemon games for GBA, you use this move to make a secret base.