The calmecac stood alongside, and in some tension with, the telpochcalli, the neighborhood school that trained the great majority of commoner boys chiefly for warfare and civic life, with a family's calpulli, its local kin-based ward, generally determining which path a boy followed, though the calmecac was not formally closed to commoners of sufficient promise. Aztec sources present the two institutions as producing the two forms of service, religious and martial, that held Mexica society together, and the calmecac's graduates supplied the priesthood that staffed Tenochtitlan's many temples, the Templo Mayor foremost among them.
Colonial-era destruction of the temple system the calmecac served ended the institution itself, and no calmecac building is known to survive intact into the present. What is known about its physical form, daily discipline and curriculum comes almost entirely from colonial-era written description, chiefly Sahagun's Florentine Codex and Duran's chronicles, rather than from standing architectural remains, distinguishing it from institutions elsewhere in this atlas that can still be visited as functioning buildings today.