Assuming you're not going for culture victory, you've taken all the prime spots with luxes etc. but in the middle of the patch of territory you control, between your cities are gaps of tiles that are not being worked. They're just ordinary grassland/plains, maybe a river that's a couple of tiles long or maybe there's a cow or two.
You've reached the Renaissance and empire happiness is no longer a factor.
Is there any reason not to found cities in this unused space?
Downsides -
the cost of building the settler
any buildings you rush buy for the new city
increased cost of social policies
reduced happiness
some wonders that require a building in every city will be delayed - but this is mostly classical/medieval wonders when you were happiness limited anyway
Upsides -
new cities will produce gold
the extra population will generate science
eventually , when your cities have all the buildings they need to be effective, they can crank out units
Someone mentioned the cost of scientific discoveries goes up too with every city founded. I hope not - that blows my understanding of the game wide open if that's the case
You've reached the Renaissance and empire happiness is no longer a factor.
Is there any reason not to found cities in this unused space?
Downsides -
the cost of building the settler
any buildings you rush buy for the new city
increased cost of social policies
reduced happiness
some wonders that require a building in every city will be delayed - but this is mostly classical/medieval wonders when you were happiness limited anyway
Upsides -
new cities will produce gold
the extra population will generate science
eventually , when your cities have all the buildings they need to be effective, they can crank out units
Someone mentioned the cost of scientific discoveries goes up too with every city founded. I hope not - that blows my understanding of the game wide open if that's the case