Saxifrage Prison is a location on Saxifrage Island in the Naljo region. The land where the prison was built used to be sacred, but it was bought and developed so the prison could be built.
The player is first brought here after being caught with a Fake ID, and put in a cell on 1F. In order to escape, the player must find Cage Keys to open the cells, as well as the Roof Card to reach the roof and find the password to the basement.
In the basement is a cell containing the legendary Pokémon Fambaco. Once its cage is unlocked it will leave and can then be encountered on Route 82.
Exit the prison by hopping over the hole to the left of your cell. This will take you to a building with a PC in it, and once outside there is a patch of grass and Palette Blue.
Speak with Palette Blue, who will give you your first Cage Key.
Head back inside, unlock your cell, and explore the prison. The player should be able to reach the bath room (left), the gym (right) which has a nurse for healing Pokémon, and other cells at this point.
Find the Fluffy Coat and two Cage Keys on 1F by going through the doorway near the stairs. There is another Cage Key hidden in the top bath of the bath room. Go to the weight room and talk to the prisoner at the table, who will give the player one more Cage Key.
(Optional) Challenge Cooltrainer Conner by unlocking his cell (above the table, on the left). He will tell the player some information about finding a password for the basement door.
Open Palette Black's cell. After talking to them, they will give you the Roof Card.
Make your way to the roof by going up a flight of stairs to 2F. Avoiding being seen by the guards, find the stairs leading up to the roof.
Once you reach the roof stairs, be prepared for a battle. Upon reaching the roof, there will be two guards waiting who will challenge you to a battle. Once you defeat them, they will tell you to talk to the officer in the weight room who will tell you the password to the basement door.
Head down to the basement and unlock the door. Once inside, the player has the option of opening the cage holding the Legendary Pokemon Fambaco.
You will find Bronze down here trying to dig his way out of the prison. Challenge him to a battle, and upon defeat he will give you HM04 Strength.
Now that you have Strength, you can move the boulders outside the building and make your way around the island. You're essentially free!
1F, Given by Palette Black in the bottom left cell (requires using a Cage Key)
1F, after going through the tunnel and walking along the blue ledges, following the winding path and continuing past the Cage Key
3 x Friend Balls
1F, In the cell at the bottom, second from the right (requires using a Cage Key)
1F, In the cell to the right of where the table is (requires using a Cage Key)
So, you're looking for a way out of here as well? This prison is managed by some lazy businessman, and guarded by fat, useless imbeciles. I was arrested for my battling and hard training methods, but... unfortunately for this world full of weaklings, I'm too powerful to be locked within these walls of crumbling cement. I battle Pokémon the way these creatures have been bred to be. You think these tiny cretins have developed their ability to breathe fire, throw boulders, and slice their enemies to battle just for sport? Of course not! I battle these creatures the way they're meant to battle: ruthless. In battle, the only true way to achieve absolute power is exploiting the weakness of the enemy while maintaining complete control of the entire field. Come, my humble trainer, and let's do battle! Haha.
You know, I feel sorry for you. You're never going to experience a Pokémon battle like I do being stuck in here. Take this HM. That's what I'm using to escape. I'm not telling you how to use it to escape; you gotta figure that out yourself.
The next time we meet, I promise. That battle will end the way I desire.