If you drive on the highway from Australia’s capital Canberra to its largest city Sydney, you pass a sign that seems strangely out of place. ‘Welcome to Sydney’, it declares. Yet all around are trees and fields, with hardly a suggestion of human habitation, let alone of the imposing architecture of a global city. It looks like a practical joke, similar to those signs they erect up in the middle of nowhere pointing the direction and distance to London, Rio, Paris and New York.