The story of the Underworld Tunnel in the Temple of the Feathered Serpent is also the story of the gifts and offerings deposited; It is the history of material culture that remained intact for hundreds of years, representing in its symbology the ideas of the world, the deities and life in Mesoamerica.

Each offering is unique and contains different elements; its symbolic richness is due to the location inside the tunnel, the most fantastic and scared thing was at the end, in the chamber of the underworld.

However, these gifts not only come from Teotihuacan but beyond Mesoamerican world; they are gifts brought from the coasts of the Gulf of Mexico and the Pacific, from the Mayan area in Guatemala and from many other places; with these, offerings were made to celebrate the investiture of the rulers or they were intended for funerary rites, among other hypotheses.

Throught the reseach areas of the Tlalocan Project, Archaeologist Sergio Gomenz Chavez and the group of specialists are joining the pieces of an ancient puzzle that, fragment by fragment, are deciphering the passage of time, the worldview of Mesoamerica and magical thinking-religious form Teotihuacan. That is why the processes of analysis, photogrammertry, restoration, maintenance, digitization and contraol of information complement the research work fo the Tlalocan Project; giving a scientific meaning to the findings and pointing out the historical processes and social, political, cuiltural and religious relationships of the Underworld Tunnel.