The Grand Est region borders four countries (Belgium, Luxembourg, Germany and Switzerland); it has more than 5.5 million inhabitants and spans 55 000 km², 86% of which is made up of fields and forests. The region has a dense river network, with the Rhine, the Moselle, the Meuse, the Seine, and the Marne all flowing through it. As well as several medium-sized cities, the Grand Est region boasts six urban areas, each of which has more than 200 000 inhabitants: Metz, Mulhouse, Nancy, Reims, Strasbourg and Troyes. The agricultural, winegrowing, automotive and metalworking sectors are key drivers of the region’s economy. Around 160 000 inhabitants of the region are cross-border workers.