Where the Emperor's/Emperess's and Princes/Princesse's Thrones are located. Royalty spend the majority of their time sitting on their mighty Thrones consulting those beneath them, and simply Ruling the Empire overall.
The Dining Hall is where the Royalty of the Destroyers feast, and enjoy themselves. Normally there are many other powerful Members of society sitting alongside them. It is a place of good fortune to their people, all who enter are lucky.
The Quarters of the Emperor/Emperess and the Princes/Princesses. It is where much of the Royalty keep themselves reserved, it acts as an escape from the rest of their society, and it is also where the Royalty normally slumbers.
The Living Quarters is the place where most that inhabit the Castle spend their time at. It is meant for meetings, and casually living like a normal, sentient being. Although it is for leisure, the Royal Guards are located throughout the entire Citadel.