The Nara Conference on authenticity marked a turning point in the history of modern conservation, with the recognition of cultural relativism. The journey to reach this was not fortuitous, but rather a theoretical construction of the concept of authenticity, influenced by different factors. Thus, the objective of this study was to understand the degree of incidence that these had, in a time frame of 30 years, in which experts would question the nature of the concept, based on its degree of operability in certain cases of conservation, such as the Sanctuary from Ise (Japan) and the Rideau Canal (Canada). They favored that the notion of authenticity, limited to historical material, will be extended to the consideration of intangible aspects, which would not only be precursors of cultural relativism, but also of the diversity of properties to be contemplated, as part of the World Heritage List.