I dont have did but I have a friend who does and I chat with their alters who want to talk since they dont know many people and occasionally visit. So for their system let me create a basis that every ones did is different of course and there is different set up for each of them, one of their alters said that another did person had a castle. For my friend, they have a simplistic way like linear, the front where two people+ can front, it looks like a living room so its the community room for others to chat and a curtain where they go through to front, and to co front they move the curtain or stay near it i think to listen in and can share knowledge by chatting through it. Then there are other rooms like the next area contains each of the alters rooms, then the next area is a childcare room for the children, and they have one main alter who cares for them/watches them in a way as a protector, thennnn even further(we have been getting further from the front) is the dormant alters who dont want to be alive/exist yknow. So my friend was here once dunno exactly how it felt to be there, they were there for a very long time. But there are other alters there who never reappear, its i believe probably around pitch darkness, maybe numb? i bet, no one talks about that area because they dont visit as a rule in the system is to not force anyone there to appear and these people want to be left alone so everyone must respect that. Some permenantly disappear there and are never heard from again. To wake one up.. well depends on the lay out of the system most likely, and some rooms are super big i suppose. I think it is up to the alter if they want to be reawakened, you may be able to call out in the forget space room.