This shot shows clearly that the catacombs are directly beneath the church. Taken from the basement, you can see the ceiling of the church through the grate at the top of the image. Underneath San Francisco de Asis and related buildings are the bones of some 20,000 priests, monks, and clergy. Neatly organized by bone type (and in some cases size), these bones have been down there for almost 500 years. After the decree of one generation, they stopped this ritual.