Can't upgrade settlements to cities

[BellyBDwarf]

So... I know that there is a button in older versions, but somehow I a missing the upgrade to city button in the current version. Even downgrading to another version won't help. Anyone?

[stadtpark-hartmut]

It's in the "Build buildings" sub-screen. Below the options of the actual buildings you can decide to construct (or destruct), there is a line with "Territory Status": it has 3 buttons: revoke city status, found city, found metropolis.

[Scribonius]

The way I found to do it is this:
Under the bar with the name of the territory and province is the terrain type(plains, forest, etc.). At the right side of that is something that tells you if the territory is a city or settlement. Click on that and it brings up the options.
Hope that helped.