Sumiyoshi Shell Mound

Sumiyoshi Shell Mound: A Stone-Walled Village on Okinoerabu

The Sumiyoshi Shell Mound (住吉貝塚, Sumiyoshi Kaizuka) is a settlement site with shell middens on the west coast of Okinoerabu Island in China Town, Oshima District, Kagoshima Prefecture, dating from the late Late Jomon to a period parallel with the earliest Yayoi, and designated a national Historic Site in 2007.

The Agency for Cultural Affairs places it on a gentle southwest-facing slope about 12 metres above sea level on a coastal cliff, with a valley to the north. On clear days Yoron Island is visible 30 kilometres to the south and the main island of Okinawa 60 kilometres away. The site extends 120 metres east to west and 100 metres north to south.

Archaeologists call this stretch of islands between Amami Oshima and Okinawa the central Ryukyu cultural sphere, and the Sumiyoshi Shell Mound offers a detailed picture of life there.

Why It Was Designated

The site was found and excavated in 1957 by the archaeology team of a joint survey of Amami Oshima by nine learned societies, and became famous for pit dwellings with walls of stacked Ryukyu limestone, a form peculiar to the central Ryukyus. When a farmland improvement scheme was proposed, the China Town Board of Education excavated from 2001 to 2005 to establish the site's extent.

The work revealed 14 pit dwellings, 3 pits and 2 shell middens, and every dwelling held a small midden formed when refuse was dumped into its hollow after it was abandoned. Because the houses were barely disturbed, it was possible to trace a change from simple dug-out floors in the late Late Jomon to pits lined with limestone walls by the Final Jomon and early Yayoi-parallel period. The whole village is estimated at around 50 dwellings.

The finds are varied. Besides reef fish and shellfish, open-ocean species such as herring and flying fish were identified for the first time in the central Ryukyus. Wild boar make up about 70 percent of the animal bones, followed by whale, dolphin and dog. One sherd of Kurokawa-type pottery and flakes of obsidian came from Kyushu, evidence of contact with the mainland. The Agency ranks the Sumiyoshi Shell Mound as an extremely important base settlement whose overall layout is now largely understood.

What to Look For

Start with the setting. From the slope above the cliff, looking south across the sea, the village's ties to the ocean are obvious; on a clear day Yoron Island sits on the horizon.

The ornaments are worth knowing about too: hairpins, pendants and ear plugs of dugong, shark and boar bone, bracelets and beads mostly of Scutus shell, and pendants of green turban shell, most of them made from materials typical of the central Ryukyus.

Across the valley, 200 metres to the north, the Tomodome site has produced pit dwellings of roughly the same period.

Visiting the Sumiyoshi Shell Mound

The Sumiyoshi Shell Mound is an outdoor site, and no official information on fees, hours or site facilities was found. Check with the China Town Office lifelong learning section on 0997-81-5151 before you go.

Okinoerabu is reached by air or sea from Kagoshima. The site is on a clifftop, so watch your footing and keep out of any restricted areas.