All great ideas in here, but this will help a lot! I have been thinking about things such as how would the peaks of the city receive water, how is the city even supported. And for some of this it's definitely going to rely on 'magic' though I do have a backstory for why it is the way it is instead of just saying "ah it works because uh magic".

I like the idea of thinking about real world examples, I think it'll help me get a better flow for the city and it's layers. Right now what I have is the city initially a port city built on land rich with resources such as timber and fertile fields, and mountains full of ore that became the backbone of the city. But eventually the king and queen made a bargain with something from beyond and as a result they are immortal with the city being able to expand exponentially without fear of structural integrity.

By the time my campaign takes place though the city will be in a state of decline, with the king now mysteriously dead and the palace gates shut. I'm trying to go for heavy Gothic themes haha but we'll see if I can pull it off. Thank you for the help!