Megastructures: Astana. Worlds Most Extreme Capital City will allow our audience to become familiar with the most extreme city on Earth - Astana, capital of Kazakhstan. In Astana, the Megastructure is the whole city. The citys radical pace of development saw it transform from straw brick huts to skyscrapers in less than 20 years in one of the most extreme climatic ranges with temperatures of ?40?C in the winter rising to +40?C in the summer. No other capital on earth faces such a dramatic climate shift.