The Wallraf-Richartz Museum is one of the country’s greatest repositories of art from the Middle Ages to the late 19th century. On the first floor, you find an outstanding collection of paintings by the medieval Cologne school (most done between 1330 and 1550). Many of the paintings and altarpieces depict legends from the lives of martyred saints who became identified with the “Holy Cologne” of the Middle Ages, St. Ursula in particular. The Renaissance section includes works by Albrecht Dürer and Lucas Cranach. A memorable collection of 17th-century Dutch and Flemish paintings holds pride of place on the second floor, including major works by Rubens and Rembrandt. In addition to important French and Spanish works, the museum boasts a rich collection of 19th-century paintings, with major pieces by the German Romantic painter Caspar David Friedrich, Gustave Courbet, Edvard Munch, Auguste Renoir, and Vincent van Gogh, among scores of others. Give yourself about 2 hours if you want to browse through all the galleries.