Minecraft Mob Prison

A simple building, created on a superflat landscape. The prison includes special cells for skeletons, zombies, and zombie pigmen, as well as a Solitary Confinement section for creepers. This section is entirely made of bedrock to prevent damage in case any creepers decide to suicide.

Present Features: Bedrock Ceiling, Watchtower (w/ redstone door opening mechanism), Individual Mob Cells, Indoor Lighting, Iron Doors and Bars

Upcoming Features: Mess Hall, Secret Underground Tunnel System, Indoor Plumbing (as if mobs need it), Execution Chamber (open-roof for undead mobs, arrow-dispenser spam for creepers)

Feel free to give me feedback on what I could put in the prison, and how to make it better. Please, don't leave any suggestions that are primarily underground. Without demolishing the bedrock or top layer, I only have two blocks of headroom underground.