The Nahua concept of heaven was one of the central issues that the missionary friars confronted as they attempted to reconcile Christian and Nahua thought in the early sixteenth century. The Nahua believed in the existence of both celestial heavens and subterranean hells, as possible destinations for individuals after death. The celestial realms, of which there were thirteen, were in general pleasant places. The subterranean realms were unpleasant. Unfortunately for the friars, the mechanisms whereby one could come to enjoy or suffer in these realms depended not on the quality of one’s life, but rather on the particulars of one’s death, the date of one’s birth, and other features of one’s existence. For instance, those who died by water, or lightening, were consigned to the heaven of the god of rain, Tlaloc. For the Nahua this post-mortem existence was corporeal, although the nature of one’s body might change in the process. The Nahua did not have any easy equivalent for the Christian soul. This essay will look particularly at the Nahuatl word for the sky, ilhuicatl, and how it functioned in both pre-Columbian thought and in the works written after the conquest with greater, or lesser, degrees of Christian input.