I want to know the answer to the following question:
Who placed the chapel's cornerstone?
All the background I'm provided with is that "King Philip IV of Spain and the Duke of Arcos suggested the building of the new chapel, and in 1647 the Viceroy, Conde de Oropesa, who had been preserved from the bubonic plague, insisted on carrying out their project.". Is that enough to answer the question?
Answer: no