Cologne, a city and heavy industrial city on the Rhine in western Germany, is the fourth largest city in Germany, the economic and cultural and historical center of the Rhine region, and one of the most important ports in the interior of Germany. It is an ancient and elegant city and a modern metropolis. Cologne, a city and heavy industrial city on the Rhine in western Germany, is the fourth largest city in Germany, the economic and cultural and historical center of the Rhine region, and one of the most important ports in the interior of Germany. It is an ancient and elegant city and a modern metropolis. The Romans built the city here, and in the Middle Ages, we saw unprecedented development and became an important church, art and education center in Germany. Cologne has many scenic spots and beautiful scenery, and the most famous cathedral is a worthy gem of Cologne.