This weekend I paid a visit to Salzburg, the westernmost big Austrian city. It is very close to Bavarian state of Germany. It only took me two hours by train to reach Salzburg from Munich. I visited Salzburg because it was one of the four metropolitan cities in the age of Charlemagne. But now Saltzburg does not have much Carolingian remnant. Its topography today was basically established in the eleventh century, the cathedral in the center of the old city, the benedictine monastery near it, and, the great castle on the mountain: