Holn is made up of three 'rings' - Outer, Middle and Upper. It's on a bit of a hill/cliff situation, hence the naming. Upper is home to the Regis Aidan Kennegan, as well as the 12 keeper families, including the Anani family - Keepers of the Arts. The 12 Keeper families help run the city and the rest of the continent, though to a lesser extent. Milo's family lives in Upper, in an estate all the way to the right. 

Middle Holn is where there are nice shops, expensive artisans, libraries, restaurants etc. It's the nice shopping district, but also where a lot of general infrastructure happens. Anyone can access Middle Holn. It is also the place where Holn University is - the main setting for Milo and Corym's section of the story. 

The university is super clear in my head! I even added the little M and C for the relevant rooms. The Stars Reach is the tallest tower in the city, and most of the university overlooks the battlefeild to the north, as it was once soldier barracks and watchtower. It was re-appropriated as a university about 300 years before the story begins. Students live there rather than at home a lot of the time. The sleeping quarters are on two floors. 

Milo's room is also extremely clear to me, so here it is! It - and the rooms of the other Keepers - are quite a bit nicer than those of other students. For a comparison, here are both Milo's and Corym's rooms. 

*I forgot to add a library to Corym's room; as a literature major, he has books everywhere! But he and his mother cannot afford anything nicer - Despite his habits, Corym was pretty much given the room to stay for free, as he excels in his classes and has very good prospects as a linguist of sorts. He never talks about it, though. 

I wish I could just project how clearly I can imagine Milo's room onto a sheet haha. It's so clear and familiar! Imagine a lot of deep blues and cozy warm whites, tea, books, parchment, scattered notes etc. 

Finally, Outer Holn is very much a poverty-stricken area. Workers, traders, and criminals alike live there. However, it's also very, very bright with life and joy. The people there take what they can, whenever they can get it. Markets, dances, and festivals all happen there, between broken homes and the fact that people can barely afford to feel like they can be certain they can eat for the whole month. This is where Corym was raised with his mother. It's not a bad life, just difficult. This is also where the temple of Lady Luck is - the one place people from Upper are usually comfortable going. 

There's a lot of 'blindness' when it comes to what life is like in Upper by those in Outer, and vice versa. Those in Upper are often told horror stories of Outer, to the point where it's barely given a chance. On the other hand, those in Outer are told that those of Upper are cruel, inaccessible, and see themselves as gods. The only place where this illusion starts to fall apart is in Middle Holn; however, the goods and services sold there are often too expensive for those of Outer Holn. The place where this line is thinnest is the University itself.