I've been to neither London nor Paris, but three times to Buenos Aires. It is a global city where I want to visit repeatedly.
In the early 20th century, Argentina became one of the richest countries in the world with the export of wheat and beef with the advent of refrigerated ships. and the wealth went towards architecture. Since it was a peripheral area where neither indigenous nor colonial culture was mature, Buenos Aires had no interest in local culture and was filled with neoclassical architecture, Art Nouveau, Art Deco, and rational architecture which derived from Europe. The lineup of those is more than in Europe, but the city has complicated shadows that Europe does not have. It is just ”Paris reflected in a cracked mirror" although I haven't been to Paris.
Anyway, a city of the immigrants from Europe, by the immigrants from Europe, for the immigrants from Europe is Buenos Aires. Its adoration for Europe was amplified by wealth and it surpassed Europe, but neither it is Europe nor it can become Europe. The sense of absence is the essence of shadows. In a sense, it is the base layer common to South America, that is, paradoxical locality. Buenos Aires as an extreme example of this is a place to overlook South America and Europe.