In Buenos Aires, the National Congress is at the western end of Avenida de Mayo--the central axis of the city--with the Government House at the other end. Such a clear alignment of institutional organization and urban structure, don't you think? Hard to believe that the site originally selected for the Congress was not that one, but ten blocks to the north (Callao between Paraguay and Charcas if you know Buenos Aires.)
I suspect that Torcuato de Alvear, the first mayor of Buenos Aires, was as familiar with Paris as with his own city, if not more. Paris may have been very much in his mind when he spearheaded the opening of a major axis cutting smack through the middle of the city's colonial blocks. Avenida de Mayo was aligned with the center of the main square, Plaza de Mayo, and the Government House. After that, it was a matter of time before they would realize that the opposite end of the axis was the perfect, and obvious, location for the Palace of Congress. Construction hadn't yet started, so the earlier choice of site was abandoned and the building moved, figuratively speaking, to this new location.
In turn, this "move" triggered another one, since the new site had been originally allocated to a grand opera theater, the Teatro Colón, that was built on a different site, about a kilometer to the northeast. In a way, you could say that Alvear took a Buenos Aires that was more like checkers and turned it into game of chess (only a couple of decades for the bishops to start cutting diagonals.)
(On a site note, with the opening of Avenida de Mayo, Buenos Aires now had two parallel "datum lines" only half a block from each other. The earlier one was the colonial Camino Real (Avenida Rivadavia) that was the main access of the city from the west and still remains the numbering divide for north-south streets. A couple of blocks from the Congress, they reconcile in the silliest of s-shaped curves.)