During the excavations of 1980-82 at Teotihuacan, the Instituto Nacional de Anthroloposia e Historia (INAH) unearthed a pyramidal-shaped building under a more recent staircase of polychrome snake heads. With the aim of making the ruins from both periods accessible to the public, specialists have undertaken restoration that draws on previous experience elsewhere on the site and which respects the Venice Charter, i.e. consolidating and integrating the structures of the second period into those of the first. -- AATA