Unfortunately there is no TV in Ruby/Sapphire/Emerald for a secret base.
Many people worldwide will be upset.
:(
Chat with our AI personalities
u can buy it in slateport
yes
You have to buy stiff boards from the lily cove departments store sale. its shown on the TVs but it is rare. they will cover the holes and let you walk into those areas.
To get an underground secret base, you have to go down there and buy it from a hiker who is selling Traps.He should have a Digger Drill for sale.Buy the Drill from him, then use in on any random underground wall, and... BING!Your secret base is born.
First up need to beat the game, then go to lily cove city and buy boards.