Archaeological sites frequently demand the excavation of buried structures for protecting the material legacy of ancient cultures and civilizations that had survived several centuries, especially from harsh weather conditions. Notably, unearthed sites often required the design of new structures to be preserved. This paper addresses the specific considerations entailed in the design of this sort of structure and the challenges to deal with structural projects that involved buildings of historical and archaeological significance. In particular, we focus on the construction of new roof covering structures in two important archaeological sites located in the Valley of Mexico: The Stage II of the pyramid of the Templo Mayor site, and the Temple of Quetzalcóatl in the Teotihuacán site. In the first case, we had an existing covering structure that dates from 1982, but whose stability became a concern after the collapse of a similar structure in the same site due to the accumulation of hail after an extraordinary storm in 2021. Accordingly, our work as structuralists included the structural assessment of the existing structure and the design of a new one in compliance with current design practices. As a result, we proposed a roof cover considering a similar design to the existing one, but with key improvements in the connections between cords and diagonals. The second case required a completely new structure intended to protect the rich feathered-snake sculptures in the stairs of the Temple of Quetzalcóatl. An international architectural competition was held for this purpose. The winning project considered a half cantilever structure, with a fixed support embedded partially in one adjacent pyramid, and additional supports on two columns. For this project, our participation was limited to the redesign of the foundation and the structural revision of the proposed structure. In both cases, the design was governed by hail load, rather than wind or seismic loads. The major challenges were regarding the foundation supports, having in mind the principles of minimal intervention and reversibility. Therefore, we proposed superficial footings that attend to both goals, protecting and preserving the archaeological site.