Premium Analysis There are several urban regions that are large economic clusters, and which are supported by more than one airport, even where the cities are not in the same country and where the airports are separated by water. One of them is in Europe, with Copenhagen and Malmö and their airports at either end of the Øresund Bridge. But an even more impressive example can be found in what is known as the Greater Bay Economic Region, which includes Hong Kong, Macau, and the Guangdong province of China, and in particular, the latter’s Zhuhai Airport. All are connected also by a bridge and tunnel – the world's longest.