Omeyocan is the highest of thirteen heavens in Aztec mythology, the dwelling place of Ometeotl, the dual god comprising Ometecuhtli and Omecihuatl.
In Nahuatl, à Âmeyà ÂcÃÂn means "the place of duality." The word is composed of à Âme ('two') and -yà  (suffix for abstractions), which gives à Âmeyà Âtl or duality; and -cÃÂn (place).
Multiple Nahuatl sources, notably the Florentine Codex, name the highest level of heaven à Âmeyà ÂcÃÂn or "place of duality" (Sahagún specifically terms it "in à Âmeyà ÂcÃÂn in chiucnÃÂuhnepaniuhcÃÂn" or "the place of duality, above the nine-tired heavens)." In the Histoyre du Mechique, Franciscan priest André Thevet translated a Nahuatl source reporting that in this layer of heaven there existed "a god named Ometecuhtli, which means two-gods, and one of them was a goddess." According to the Codex RÃÂos, the History of the Mexicans as Told by Their Paintings, the Histoyre du Mechique, and the Florentine Codex, the goddess of fertility and creation Tà ÂnacÃÂcihuÃÂtl and her counterpart Tà ÂnacÃÂtÃÂcuhtli resided in à Âmeyà ÂcÃÂn, creating human souls and sending them to earth. Sahagún clarifies that their names are epithets of à ÂmetÃÂcuhtli (literally "two-lord") and à ÂmecihuÃÂtl ("two-lady"), giving as an alternate name of à Âmeyà ÂcÃÂn "in tà ÂnacÃÂtÃÂcuhtli ëchÃÂn" ("the mansion of Tà ÂnacÃÂtÃÂcuhtli").
There is some evidence that these two gods were considered aspects of a single being, as when a singer in Cantares Mexicanos asks where he can go given that "à Âme ihcac yehhuÃÂn Dios" ("they, God, stand double"). The History of the Mexicans as Told by Their Paintings reports of the two that "se criaron [sic] y estuvieron siempre en el treceno cielo, de cuyo principio no se supo jamás, sino de su estada y creación, que fue en el treceno cielo" (they created themselves and had always been in the thirteenth heaven; nothing was ever known of their beginning, just their dwelling and creation, which were in the thirteenth heaven). In the Florentine Codex, Sahagún relates that Aztec midwives would tell newborns after bathing them, "You were created in the place of duality, the place above the nine heavens. Your mother and fatherâÂÂà ÂmetÃÂcuhtli and à ÂmecihuÃÂtl, the heavenly ladyâÂÂformed you, created you."
A song from the Historia Tolteca-Chichimeca mentions "ay à Âmeteà Âtl ya tÃÂyà Âcoyani," literally "two-god, creator of humanity." Many scholars (most notably Miguel León-Portilla) interpret this name "à Âmeteà Âtl" as "Dual God" or "Lord of the Duality," seeing it as a fusion of à ÂmetÃÂcuhtli and à ÂmecihuÃÂtl, existing primordially in à Âmeyà ÂcÃÂn. León-Portilla further argues that Ometeotl was the supreme creator deity of the Aztecs, and that the Aztecs envisioned this deity as a mystical entity with a dual nature akin to the Christian concept of the trinity.