The Church of San Fernando is Guaymas's main Catholic church, a colonial-era building on Serdan Street that has been at the centre of the city's religious life since the Spanish colonial period. The facade is relatively modest by Mexican standards — Guaymas was always more of a commercial port than a religious centre — but the interior has good examples of colonial religious art and remains an active parish.
The church is best visited during morning mass or on feast days, when the square in front fills with worshippers and vendors. The adjoining plaza gives a good vantage point for the street life of Serdan and the mix of nineteenth-century commercial buildings that line this stretch of the city.