By Tobias Carroll Most of the time, when workers are called in to modernize a building, it’s a relatively self-contained job. Sometimes, though, it turns out to involve a trip back into history. The latter was the case recently in Mexico City, where a planned renovation of a power station involved construction workers finding the remains of a building that hearkened back to the days of the Aztec Empire. As Smithsonian Magazine reports, the building the workers found is likely close to 800 years old. The article notes that the building in question seems likely to be a residence, with a total si…