Danish architect helped Aussie cities find their mojo

Jan Gehl says a good city is like a good party; people stay if they are having fun. (PR IMAGE PHOTO)

A household name in Australia he's not, but Jan Gehl is a big reason Sydney, Melbourne and Perth found their razzle dazzle.

Thanks largely to the 90-year-old's knack for transforming ghost towns into thriving central precincts, the three cities have surged in global livability rankings.