From the pre-Hispanic period to the present, religion has pervaded the life of people in this region. Since it was imposed in the early 16th century, the Catholic religion has permeated and molded popular culture. As in other parts of Mexico, indigenous beliefs and practices, such as those of the Xochimilca, were not completely eradicated. Instead, many were integrated and readapted to Catholicism. One example of this is the building of churches over former temples and other sacred sites. These churches' decorations often have indigenous elements as well. Despite the fact that 91% of the population self identifies as Catholic, there are still many indigenous traditions related to the agricultural cycle. A more important syncretism has been the many religious festivals that occur through the year, and the means by which these festivals are sponsored and organized. Much of religious practice in the borough is through symbolic processes that work to produce a kind of social cohesion. The most visible of these are the large civic/religious festivals.