Imagine [your favorite urban megacenter], thrice more crowded, walled and with at least 3 ceilings. Instead of streets of mixed commerce you have entire streets back to back of aisles/sections with entire buildings for the same type of product - and some weird overlaps, like police stations also being abattoirs/butcheries.
There are 50 night clubs clumped together in the same street, some atop one another in 50 stories-tall buildings, ambients sectioned by music genre and DJSs. There are food stalls, threre are drug stores, there are gun stores, all club-themed.