Yes but even if a city is designated as capital, will she have special features that distinguishes it from other cities in the game? What do you think of ?
It may get complicated being there is only one map per city. However, say you do build a capital city, whenever you build a different map it may ask you if you would like to include a capital thats in the region, and it will give you a list of capitals you did build. you could also have an option to add one at any time. the cities and capital would just sync and share information x,y and z and any options available to them.
These capitals could be the seat of government, economical, cultural, and intellectual centers. Depending on how you build a capital city, they could give specific boosts such as economical, cultural, health/crime, demographic and intellectual to future/current cities being built.
The cities that claim a capital may have to pay x amount in taxes to it, so the more cities that claim a specific capital, the bigger a capital cities budget gets aside from whatever the city produces itself. In turn, any surplus the capital has it can then write loan free grants to any cities under it. federally funded ehhhh. perhaps the more cities you have attached to the capital can be a prerequisite (total built region population) in unlocking future build options in the capital itself
As the capital grows, different functions could be unlocked via award. IE department of education, Federal drug administration, united nations, etc etc, basically any kind of govermental/captial building one can imagine. Thus giving boosts to cities that are part of the capital.
different buildings such as:
capital building.
presidential building (white house) or pm, kings palace etc
several embassys.
different capital city monuments from around the globe.
government museums/memorials/theaters/library
the bureaucracy building from some simcity game
national cemetery
national college
Supreme court
National defence
united nations
etc
etc
if one is actually building a capital city, thats a map within itself.