I guess the towers need not be so far away from the city.

Does not need cubical frames to be built either.

 

Only if. Regulations say it must be outside of certain areas...

 

If aiming complete height,

 

fun idea: (may not be so practical)

 

Rockets are built in slices of cylinders.

 

If a giant slice of cylinder, divided into however many

required portions, interlocked and dropped,

increasing in height,

and as it does,

 

4 interlocking (or 8) or however many needed crevices

in the outer surface of this cylinder, to be dropped

cubes, to be welded, at the most bottom, the longest

length extending out to many cubes, (to support

the cylinder) and incrementally brought up,

like stairs as it goes up. So it looks like a fin.

 

And top of this, is a metal frame tower,

working as an antannae.

 

Which would look like a giant rocket ship.

 

Of course, these are in mix of cement and metal.

 

Not purely metal. That would be expensive.

 

Less area required, simplicity.