We stayed for a year on the corner of Ciudad de la Paz and Palpa, technically it's Colegiales, but just one block from Av. Cabildo. The side streets in that area are generally quiet enough outside rush hour, lined with jacaranda trees, and you can find most things you need close by: it's also in walking distance of Chinatown and the Belgrano municipal market. There was a building being finished in Palpa at the start of the year, and there are quite a few projects in the area. Walking around and taking photos of the building projects sounds like a good idea.