London or that make it awesome - yeah, there are some shallow clowns who go there for that stuff but they're in the minority.
The greatness of London is in the simple fact that more to offer in depth and range of history, culture and architecture than almost any place on earth. It was the "capital of the world" - in commerce and political power - for more than a century. No city in modernity has had a longer run - and in the United States, the economic power, the political power, and the cultural power are divided between multiple big cities. In the British Empire, London was the epicenter for all of it. The monarchy is mainly an afterthought.