There are low security and high security cells. In the low security cells, prisoners are surrounded by crying obsidian on all sides except for an iron door in one wall, which is where the visitors come in. In the high security cells, the walls regenerate with cobblestone, and respawn via the squilly bed glitch from below. Visitors enter via the ceiling.
Outside Defence
There is a lot of crying obsidian on all sides. Also, there are a lot of elder guardians to give mining fatigue 3 constantly. There are supposedly area bans but I searched for months and I still couldn't find any.
More Security
There are over 9000 keycard-openable doors in the guard areas.
