Zaun and Piltover are probably part of the same giant metropolis now

It's not so weird when you think about it. Technological progress, especially the process of industialization has caused a massive growth in cities.

I know that from my personal experience as well. My hometown is actually pretty much three towns that have grown together so much you don't even really know where one part ends and where the other starts, even if several centuries ago they had been several kilometers apart. What spikes my curisosity is actually the grey area right on the border between the citiy cores of those two, as that is probably lawless area... either slums or industial districts - or abadonned industial buildings, that also works. Would be the area we saw in Ekko's teaser.

The bigger question is actually... does Zaun even have some kind of goverment? Piltover has a police force at least, but Zaun seems like hypercapitalistic anarchy to me...