Dat hellije Coellen" (Holy Cologne) was Germany-s largest city known in the Middle Ages. The citizens of Cologne maintained that it had "as many churches as days in the year-. Their self-confidence is still to be seen to this day in the building of the Rathaus (Town Hall) and the Gürzenich, which originally housed Germany-s largest banqueting hall. The trade relations of Cologne-s merchants extended from the Orient to the Occident, and the city developed into one of the major trading centres in the world. Some of the impressive patrician houses are still to be seen, for example, "Saaleck-, "Zum Seil-, "Zum St. Peter-, the "Delfter-Haus" or the "Zur Brezel and zum Dorn" double-house. The world-famous Cologne Cathedral with its gigantic dimensions and rich furnishings has a breathtaking effect on its visitors even today. After the foundation stone was laid in 1248, it took more than 600 years until the Cathedral was finished in the 19th century. The many well-preserved stained-glass windows and the golden glow of the Shrine of the Three Kings determine the appearance of the interior first and foremost.