in world of My Little Pony where magic is all around in this universe is humanoid so hands and feet and that King Sombra and Queen Umbra taken over the powers, but they did not Eliminate as that wouldn't be as fun so they created a special prison

The prison is colour coded for the races, Green for earth types ones without magic, Light blue for pegasi ones with wings, purple for unicorns , and Red the more secure place for Alicorns. Each section works independent from each other for security reasons

Inside the prison are many who have been sent due to the new royals so there is main 6 being Twilight, Appljack, Rarity, Fluttershy, Rainbowdash and pinkypie but there is also Celestia, Luna and Candance. As each section of the prison uses different types of restraints to fit the inmate like anti magic horn rings and handcuffs of different strengh and wing cuffs

while your the Warden giving you full control over the prison as you and each guard where hand picked by Sombra and Umbra for loyalty and to not be swayed by the inmates, while new royals are evil they know to keep strict rules as they want the prisoners alive physically, As Umbra and Sombra do pop into the prison to have there persnnel fun

the prison is clean almost perfectly as inmates are often forced to clean, while floor is made of metal cubes making them into sections with a non conductive lining, while the walls are concrete with steel bars inside as windows are made of reinforced glass, with security doors. But in each section there is only 3 rooms that are comfortable as one is guard breakroom, a security room and a private room. As your office is comfortable and set to your preference