Complex sentence: Chenggong is the chief zone for the expansion of the city of Kunming, 20 minute drive away--it is the site of the new Kunming City Hall, and new campuses for Yunnan University and Yunnan Normal University.
Split into simpler sentences: Chenggong is the chief zone for the expansion of the city of Kunming, almost a 20 minute drive away. It is the site of the new Kunming City Hall, and new campuses for Yunnan University and Yunnan Normal University.