Spanish conquest of the Aztec Empire
After the Spanish conquest of the Aztec Empire, the Spanish laid out their own capital over the ruins of Tenochtitlán. The eastern end of this city corresponds to the La Merced, San Lázaro and Candelario de los Patos neighborhoods. However, these areas were overpopulated and un-hygienic because of the low, muddy condition of the lands here next to the lake, constantly subject to flooding.