The Iha Shell Mound (伊波貝塚, Iha Kaidzuka) is the site of the remains of an ancient settlement on Okinawa Island. Located in the Iha district of Uruma City, south of Ishikawa, the site sits on a large limestone fault slope, and dates from the late Shellmound period of Okinawan archaeology, coinciding with the late Jōmon period, c. 2500 – 1000 BC.[1] The shell mound is approximately 60 centimetres (24 in) thick and covers an area of 150 square metres (1,600 sq ft).[2] The site was first discovered in 1920 by Ōyama Kashiwa, confirming that Okinawa was settled by ancient peoples, and is one of only a few fully excavated shell mounds in Okinawa.[1] The site includes remains of fish and animal bones, earthen and stoneware, and goods made out of horn.[3]