In this study, we employed the 5-meter Accuracy Digital Elevation Model (DEM) developed by the Geospatial Information Authority of Japan, to analyze the spatial distribution of Yayoi-period archaeological sites. Rather than relying on conventional regional cross-tabulations—such as prefecture-level classifications—this approach adopts a Geographic Information System (GIS)–based analysis that enables higher spatial precision as well as more intuitive and visually accessible interpretation. Through this methodology, we aim to reconstruct the geographical conditions of ancient Japan at the end of the Yayoi period, approximately 1,800 years ago, and to offer a new perspective on the long-standing debate concerning the location of Yamatai (Yamataikoku). The results of analyses using the 5m DEM substantially increase the likelihood that Yamatai was located in northern Kyushu. In addition, northern Kyushu exhibits highly distinctive patterns of land use that vary markedly by region. The areas surrounding present-day Asakura City and Ogori City appear to have been specialized primarily for military purposes. In contrast, the Yoshinogari site—one of the largest Yayoi-period settlements in Japan—shows a pronounced specialization in agriculture, particularly large-scale wet-rice cultivation. The area corresponding to modern Fukuoka City, meanwhile, functioned as a major urban center in which both military and agricultural functions were concentrated. Furthermore, the “Jimmu’s Eastern Expedition” undertaken by the first Emperor Jimmu cannot necessarily be dismissed as a purely legendary event; it likely reflects certain historical facts. By introducing a GIS-based approach that has been relatively underutilized in previous research, this study serves as a pilot project while simultaneously representing an ambitious attempt to expand the horizons of visualization in ancient Japanese historical studies.