There are secret bases in Pokémon Ruby Sapphire and Emerald. In Diamond Pearl and Platinum, you have underground bases.
Yes, about once a week at 6pm on the roof of Lilycove Department. To unlock them, you have to watch an advert for them on the TVs which appear randomly. At the sales you can buy wooden planks to cover holes in secret bases.
In generation 3, the only games that include "secret bases" are Pokémon Ruby, Sapphire, and Emerald. The LeafGreen and FireRed, Kanto reboots, unfortunately did not include this particular feature.
Ruby - 2008 Ruby's Secret Storm 1-4 was released on: USA: 2008
If you mix records with your friends and they have Lv100's you can raise your pokemon's level by visiting your friends in their bases and battle.
The Secret of Ruby Scorpion - 2007 was released on: USA: 2007
Secret power can make secret bases for you find a tree or bush or indent in a wall then use secret power on it and inside is a base this is a place where you can decorate and customize your own place! Also if you mix records with other ruby and sapphire and emerald games you can battle other peoples secret bases! Secret power also can inflict opponents Pokemon with poison, flinch, parlyze, sleep, and can lower stats like speed.
They can be found in Rock Tunnel at about level 18.
No
I would say the one on the way to de-activate the generator at new mauville near the cycling rode in Ruby, Sapphire, and Emerald.
you use a mach bike to go over the holes really fast, but you have to back up little and then go over with out stoping
no