WI: Brasilia-like new city as Turkish Republican capital?

What if upon the independence of the Republic of Turkey, Atatürk and others decided that a new planned capital should be built instead of moving the capital to Ankara? Where would such a city be most plausibly located, and how would it look? How would a new capital affect centralizing initiatives?
 
Ankara was pretty small and irrelevant before becoming the capital, and (at least for the first few decades) it's growth as the capital was very strongly guided by the government. So it essentially was a planned capital.
 
Top