The first thing to note about the 'Eos' present in Final Fantasy XV: A New Empire is that it has nothing in common with the world presented in Final Fantasy XV. It consists of grassy lands with lakes here and there, with stone arches (à la the Duscae region) scattered in several places. Each server ('realm') of the game has its own randomly generated map.
The city you build in the game is unnamed and architecturally is not related to the civilizations present in Final Fantasy XV. The city itself consists of several important buildings that are locked in place, as well as production facilities and other smaller buildings that can be built and moved at will.
Please see here for a list of the available buildings you can populate your city with.
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