A census taken by the last Quipucamayoc indicated that there were 12 million inhabitants of Inca Peru; 45 years later, under viceroy Toledo, the census figures amounted to only 1,100,000 Indians. While the attrition was not an organized attempt at genocide, the results were similar, largely resulting from smallpox and other Eurasian diseases to which the natives had no immunity. Inca cities were given Spanish Christian names and rebuilt as Spanish towns, each centered around a plaza with a church or cathedral facing an official residence. A few Inca cities like Cuzco retained native masonry for the foundations of their walls. Other Inca sites, like Huanuco Viejo, were abandoned for cities at lower altitudes more hospitable to the Spanish.