Regensburg is probably the oldest city on the Danube, and the Danube passing through it has flourished in various historical periods as a military barrier and a trade passage, and has also allowed the city to flourish. Today, the city is also selected as a UNESCO World Heritage Site. Fortunately, in World War II, Regensburg withstood heavy air strikes, but the old city was not affected, Regensburg survived the bombing of the World War, which was a miracle in Germany, and many of the city's historic buildings were completely preserved.