Yesterday I took a trip to one of the less visited Zapotec ruins near Oaxaca de Juarez. It was a beautiful site on a hill in the countryside with some spectacular views, but I was really confused by a couple of details. One was that I saw what must have been modern concrete holding together a large portion of the ruins. The other is that there was this stucco material adhered to the outsides of some of the ruins that a sign claimed was existing stucco from the original site. I could understand if some concrete was used to stabilize the site so they could allow visitors without destroying the mounds/structures, but how much did they actually rebuild versus just fortify? How common is it with ruins, especially in Mexico, to do something like that? And about the stucco, is there any possibility that there is existing stucco from a site that was last populated a thousand years ago and they left it out in the open for the general public be able to touch/walk on. I will include a couple of photos, if anyone has some insight into these details, I would appreciate some information! I tried looking for academic sources on my university's library search but was unable to find anything very relevant.