Rijn

   One of the most important rivers that empties into the North Sea. Other rivers that flow into the same delta are the Waal, Meuse, and Scheldt. In Roman times, the Rhine was the northern border of the empire; along the river Rhine and the Danube, a num ber of fortifications were erected against German invasions. During the Middle Ages, some of these strongholds became towns, such as Utrecht (near ancient Dorestad) and Nijmegen. The Rhine was an important waterway for the transport of travelers and all kinds of merchandise. During the 19th century, problems between Prussia and the Netherlands regarding the international status of the Rhine were solved by a convention at Mainz, which declared the Rhine free of toll barriers (especially on Dutch soil). Today the Rhine is still a ma jor waterway, along which products are transported between Ger manyand Holland, whereas Rotterdambenefits from its location as a center of transshipment.