Mexico is known for nothing if not major pieces of religious heritage for Catholics and christians. Iglesia de San Fernando is a church that was dedicated to King Fernando III. King Fernando III was infamous for his intolerance, having banned Muslims and Jews from the Spanish country, and the church has a sordid history of having been used to carry out punishments against heretics. The Spanish Inquisition and other barbaric practices are a big part of early Catholic history, and, sordid as they are, are nonetheless an important element of interest to all history and theology buffs.
One of the larger religious sites in the city, Iglesia de San Fernando stands as a must-see for students of history, religion, Mexican culture or architecture. Today it still serves as a church, but its legacy also makes it an important piece of cultural heritage of interest to even the agnostic or atheist visitor.