The entire way Haviah, Aedolis' largest city and the capital of the nation, is set up is reflective of its culture. Rather than be built outwards like most cities, Haviah was built upwards with the lowest level built roughly half a mile over the earth. Below it lies a metal warren that extends down to the actual ground level, the foundations of the city, though there are no gaps in it to the outside; it is closed off. The Midhaven can be found here.
As for the levels themselves, there is the lower level which has an artificial "ground", home to lower caste citizens, a dark and corrupt place no one would willingly wish to live; there is the middle level, home to middle caste citizens that live comfortable, if oblivious, lives; and there is the upper level that opens up to the sky, with aeries built on the roofs of the buildings to accommodate the dragons. The upper level is home to upper caste citizens in charge of the other castes' lives. The higher up a person lives, the higher on the social ladder they are. Movement between these three levels is virtually impossible, however, as access to other levels is restricted.
However, Haviah does has excellent public transportation in the form of shuttles and subways. There are no cars, but some citizens own bicycles, motorcycles, and scooters.
Another interesting fact about the city's structure is that due to all the buildings and skyways in the way, it's impossible (or at least exceedingly difficult) for a lower caste citizen to look up and see the higher levels and for the higher caste citizen to look down and see the lower levels. There's simply too much stuff in the way. As can be imagined, this has been the source of many a lower caste citizen's paranoia as it gives a constant sense of being watched (and rightfully so as hidden surveillance cameras monitor the entire city), but they cannot actually see the people in control of their lives. It's very unlikely that a lower caste citizen would have ever even seen a dragon; again, with all the skyways in the way, dragons are simply much too big to get down into the lower level. They need humans for that.
The city's set up does pose a potential hazard to its citizens. If there ever were an emergency, while it would be easy for upper caste citizens to evacuate, middle and lower caste citizens could wind up trapped.