Colonial-style church. It formed part of the convent of La Merced. It is a colonial-style church which has been rebuilt on two occasions. In the 17th century it formed part of the convent of la Merced. It was destroyed by several earthquakes in the 18th century, and its reconstruction was begun in 1775. However another earthquake, this time in the 20th century, forced it to close once more for a further reconstruction. It is laid out in the form of a basilica with three naves, and is separated into five compartments. It was declared a National Monument in 1970, and became a cathedral in 1953.