I wrote yesterday how European cities, both large and small, love their cathedrals. Cologne is no exception. Cologne Cathedral is a massive, Catholic cathedral located right downtown near the banks of the Rhine River. It has the distinction of being the tallest cathedral, but that was back in the 1800s. There is room for over 20,000 people inside the cathedral, which is mind boggling since this is larger than some stadiums and arenas. If you do the tour, there is a crypt under the cathedral that has artifacts dating back to the 4th century. This is a great way to spend an hour or two in Cologne.