The methods by which territorial extent was understood in early Japan, spanning from the Yayoi period (third century BC–third century AD) to the Kofun period (third–seventh century AD) remain largely unknown. Nevertheless, it is likely that a certain level of geographical knowledge was necessary for interregional negotiation and the subsequent processes of political consolidation. Spatial patterns can be observed in the distribution of archaeological sites and prominent mountains. For example, when major ruins in the former Izumo Province, where numerous bronze artifacts have been excavated, are geographically linked with peaks such as Mt. Daisen and Mt. Sanbe, emerges as an approximately large-scale isosceles triangular configuration. Similarly, connecting Mt. Fuji, Mt. Daisen, and Mt. Takachiho—three of Japan’s most distinctive landmarks—also produces an enormous triangular arrangement. These triangular groupings are further associated with shared mythological traditions, which may suggest that a broad geographical awareness existed during this early period. Although definitive conclusions cannot yet be drawn from surviving records or material evidence, this study presents the relative spatial relationships among key mountains and archaeological sites. In addition, as an exploratory reconstruction, the Japanese archipelago is represented using a stick chart (branch-type map), a primitive cartographic form in order to examine possible modes of early geographical perception.
Kaoru Yoshida (2026) studied this question.