Cologne Cathedral is a landmark of the city of Cologne as well as one of the most popular sightseeing attractions in Germany. Germany’s most laborious building works took 632 years to be completed. You can reach the top of the third-highest place of worship in the world via the 533 steps. The climb is worth it for an unbeatable view of Cologne. By the way, it’s a Cologne tradition to greet the Cathedral when you walk past.