One of the most impressive structures in the city, The Metropolitan Cathedral was built ON TOP of a sacred Aztec site adjacent to the Templo Mayor over the course of 250 years. Legend has it that Cortes himself laid the first stone of the church that was taken from the temple of the Aztec god of war.
The center of the Aztec Empire, the Templo Mayor (Main Temple) was once the site of sacred offerings and an altar for worshipping the deities of war and rain. The Spanish covered over and buried the temple when they conquered the Aztec people, but over the years it has been uncovered. It's amazing to see this in the heart of the city!