Belgium is bordered on the N by the Netherlands and the North Sea, on the E by Germany and the Grand Duchy of Luxembourg, and on the W and SW by France. Brussels is the capital and Antwerp is the chief commercial center and one of the world's major ports. Other important cities include Ghent and Liège. The terrain is low lying except in the Ardennes Mts. in the south. It is crossed by the Meuse and Scheldt rivers and by a network of canals. Belgium is one of the most densely populated nations in Europe. Historically, the country comprises two ethnic and cultural regions, generally called Flanders and Wallonia-Flanders embracing the northern provinces of East Flanders, West Flanders, Antwerp, Limburg, and part of Brabant, and Wallonia comprising the remainder of Brabant, Hainaut, Liège, Luxembourg, and Namur. The dividing line runs roughly east-west just S of Brussels. Flemish (a Dutch dialect) is the official language in Flanders, while French is official in the south. The French-speaking people are commonly called Walloons, although the term once referred chiefly to those people in the area of the city of Liège who spoke Walloon, a French dialect. Brussels is bilingual, and German is spoken in a small section of Liège province. About three quarters of the population is Roman Catholic; the balance is largely Protestant, although there are Islamic and Jewish minorities in the cities. There are universities in Brussels, Ghent, Liège, Louvain, Mons, and Antwerp. The country also has numerous colleges, and schools of music, architecture, and art. Many cities (most notably Brugge and Ghent) have preserved their medieval architecture and art, which attract thousands of tourists annually. The North Sea coast is popular in the summer.