Why it looks like this

Buenos Aires is the Spanish colonial rulebook at maximum size. The Law of the Indies told colonial towns to build a central plaza and a checkerboard of square blocks — and the city simply never stopped repeating them. The grid runs inland from the river with remarkable patience, absorbing suburb after suburb.

Even its extremes follow the grid: Avenida 9 de Julio, cut through the city in the 1930s, is a full block wide — up to 140 metres — one of the widest avenues in the world.