A simple prison comprised of eight cells, four to a side. Each cell has an individual light-source (toggled by lever) above the cell as well as a 'kill switch' which dumps lava (or water) onto the prisoner. Lastly, at one end of the hall, resides a lever which controls sticky pistons over the hallway - the sea lanterns in the ceiling are pushed aside, and lava pours into the guard area. This is good for handling monsters that may spawn outside their designated cells.
Built with redstone, repeaters, stone bricks, stone, lava, water, iron bars, sticky pistons, sea lanterns and spawners.
Feedback is welcome.