Why Rome, Venice is so beautifully built? Why Italians are master artists? What makes them so?

I have never gone to Italy. But I have seen the cities of Rome and Venice in videos and photographs in magazines. And I was really astonished seeing the beauty of these two cities. I have a relative who works in navy and he has toured almost every portion of the world. When I asked him that after visiting the entire world which city do you consider as the most beautiful city in the whole world, he replied that it is Rome. I wonder, why it is so? What is the reason or inspiration behind the Italians becoming such great architects of those magnificent buildings, fine sculpture artist, beautifully arranged city planners? And why other cities of Europe have not succeeded to come upto that level?