Visitors tend to stick to the surface, which mimicked the cities back on Earth. But they're missing out. The nightlife doesn't really get interesting until you get past Level 51. Concept art by Pat Presley.
Seriously, if you want your eyes to bug out of your head, go visit Presley's portfolio site and his ArtStation gallery. Presley is a concept artist who has done work for Lucasfilm on Clone Wars and Star Wars Rebels, but his other concepts are just glorious, filled with enough environments, vehicles, and creatures to keep a person inspired for a good long while.
"District 19" is featured with permission and was spotted on r/ImaginaryCityscapes.