Hijiyama Shell Mound (prefectural historic site)

The existence of a shell mound at the southern foot of Hijiyama has been known since the Taisho era, but it was not until 1932 (Showa 7) that a large number of artifacts were actually unearthed during military construction work. A large number of discoveries were made during full-scale excavation work carried out after the war. The shell mound consists of three shell layers and a layer containing pottery and other items below that. The items excavated from the lowest layer are the oldest, and the Jomon pottery found there has many features such as rope and spiral patterns, and notches in the mouth, which suggests that it was made in the late Jomon period. In contrast, the pottery excavated from the upper shell layer has no patterns, and both the inside and outside of the vessels are well polished and shiny, dating to the late Jomon period. This means that this shell mound was probably made sometime between the late and final Jomon periods. Stone tools such as stone sinkers (for attaching to fishing nets), stone arrowheads, and stone spoons (for skinning animals) have also been excavated. These were made from andesite found in Shikoku and eastern Yamaguchi Prefecture, suggesting that there was trade with these regions at the time. As for the shells that make up the bulk of the shell mound, about 40 different types were found. The most common type was the clam, accounting for 70% of the total, followed by oysters, Japanese littlenecks, Japanese oysters, mirror shells, cockles, and red squids. Interestingly, the number of clams, which live in salty areas, decreases as you go up the layers, while the number of cockles, which live in areas where fresh water enters such as river mouths, increases. This is probably because when the shell mound first began to form, the area around Hijiyama was completely sea, but the sediment carried by the Ota River made it almost connected to the mainland. Small amounts of deer and fish bones can also be found mixed in with the shells. A detailed examination of the Hijiyama Shell Mound reveals the image of people who lived in this area a long time ago, catching fish, collecting shells, and hunting with bows and arrows. It is thought that the shell mounds cease to exist at the end of the Jomon period because as rice cultivation techniques were introduced, people moved away in search of land suitable for this. Location: Hijiyama Honmachi, Minami Ward, Hiroshima City Date of designation: March 22, 1950 (Showa 25)