In Moscow the problem is that in fact it's a big village that's over 850 years old.
The city was built in circles. Inner circle: Kremlin, a citadel. Then - a Chinese-town (Kitay-gorod), another brick wall, only a little lower, then - White town, Ground town, both having their own walls. Kitay-gorod wall was almost completely destroyed in the 1930s, it was incompatible with modern traffic. The last wall was built in XVIII century, "Kamer-Kollezhskiy val", Moscow Circular Railway is now on top of it, and it remained a city border until maybe 1945.
So we have this stupid radial structure, unlike any modern city we suffer from heritage of the times when the city had to defend from Tatar nomads and neighbouring princes. Kremlin was buit as it is now in 1400-1550. So the Kitay-Gorod walls and streets that follow the old wall lines.
And now officially we have 10 million people living here, it's obviously an underestimation, at least 18 million by the subway statistics, some sources say that we have up to 27 million people living in this village...