The article focuses on the Eiffel Tower, three of the largest buildings in the world in the second half of the 19th century-the Crystal Palace made of iron, the Brooklyn Bridge made of steel, and the Eiffel Tower are the products of architectural innovations. The Crystal Palace was built for the Expo and was relocated to Sydenham after the expo to host sculpture, painting and architecture exhibitions and concerts, while the Brooklyn Bridge was designed to connect the two boroughs of New York City and drive up housing prices. Unlike both of these, the Eiffel Tower's purpose seems to be merely to give people a glimpse of Paris. It's not a defense tower, it's not a spiritual anchor, it seems to be the butt of jokes, and many artists scoff at it. But ordinary people fell in love with it at first sight. Slowly it took on a new meaning. During The Second World War, soldiers hung the tricolour flag on the top of the tower, which did not fall down. Without it, Paris would not be Paris. The Eiffel Tower is the king of the towers, a great human symbol.