 The Metropolitan Cathedral, dedicated to the Assumption of the Most Blessed Virgin Mary, occupies the north end of the Zócalo.The site originally was part of the Aztec Sacred Precinct (called the Teocalli) and contained the main tzompantli, or rack for the skulls of sacrifice victims.The first church was erected between 1524 or 1526 and 1532 and was elevated to the rank of cathedral on 2 September 1530 by Pope Clement VII.