“Huaca” is one of the key words used in the ethnohistorical and archaeological vocabulary about the Andes today. From an uncritical reading of Garcilaso’s Royal Commentaries, this Quechua term is often considered to mean “sacred object or place”. By examining historical sources as well as modern linguistic information, this article shows that “huaca” (wak’a) meant ‘split’ and that, in the religious field, this term designated transportable stones considered as detachments or duplications of a mountain- dwelling mythical ancestor. By extension, wak’a also applied to the sanctuary that housed these stones, to the same divine ancestor and to stone amulets emanating from him. Numerous indications suggest that the cult of the huaca stones is of Inca origin.