Here is some ideas I was working on (sorry if not complete).
By placing prisons inside of prisons you can reduce the need for support staff. Prisoners from less punishment areas can serve those in highest. Escape from innermost areas are discouraged through multiple security places they would have to go through. Overall number of guards available is more than a normal prison would have should trouble arise.
(1) Isolated area: Federal Land.
(a) empty at least a couple of miles in all directions , no roads.
(b) to prevent escape attempts, contraband, etc.
(2) Only access is by train. Preferably underground.
(a) Everything / Everyone will be searched before getting on the train and before entering Prison city.
(b).Train will be connected to an airport, bus stations.
(3) Whole city will be surrounded with fences with guard towers.
(a) They will shoot down drones, etc. trying to enter the city.
(4) Barbed wire around the city to foil escape attempts.
(5) Outer layer: Infrastructure.
(a) Housing, hotels, schools, hospitals, police, courts, etc.
(b) Power plants (small nuclear plants), water treatmentment.
(c) Commercial stores to support people: groceries, Starbucks, Theaters, etc.
(d) Parks and recreation areas.
(e) Limited number of vehicles and roads. Public transportation is free, including bicycles, etc.
(6) First inner section: Minimal security.
(a) Surrounded by a fence.
(b) Open area for homeless.
(c) Separate are for drug users. A place to buy and use cheap and legal drugs. Voluntary settlement.
(d) Housing of “half-way” prisoners.
(e) Separate are for child offenders who have finished their sentences.
(f) Commercial and support businesses. Additional hospitals, clinics, court buildings etc.
(7) Second inner section. Surrounded by fences and guard towers.
(a) “Country Club” prisons.
(*) Innermost level: Hardest prisoners. Terrorist. Lifers.
Prison design:
(a) Prison cell: singles.
(b) Use clear walls. Cameras watching and recording all cells, paths, etc.
(c) Each cell will include a television (behind protection - behind clear walls) (for communication and enrichment: Nature shows, education, etc)
(d) Each prison will have access to a tablet (embedded in wall?) to communicate with families.
(e) Each cell will have a toilet, drain and shower head embedded in the ceiling. (Maybe a sliding door protecting the shower head when not in use.
Of course every conversation will be recorded to avoid abuse. The intent is to not punish children of prisoners and to give them an incentive to be cooperative.
Violent prisoners will be placed in cells where transportation is managed through cages. They will enter and exit the cage (clear plexiglass? walls) into the cell. The cages will travel on a rail to where they need to be (infirmary, court, etc). Some cages will be long enough for a stretcher
Most court procedures could be done through the tablet (facetime, zoom).