Hyotan-ana cave is located at Iwaizumi town, Iwate prefecture, where one of the biggest areas of Limestone formation in Japan. There have been searched many caves or shelters around here. The cave lies on slope of the height of 158 m and about 50 m above a river running below. It corresponds to the highest terrace, supposed to date back to around 300,000 years BP.
The cave is about 20 m in width and depth and 10 m in height and has a small chamber room, measured 10 m (width) x 4 m (depth) x 3 m (height) in the rear part. So far lithic industries have been discovered from several horizons at Zone A, C, D, and E during 4 seasons since 1995, which almost belong to upper to middle paleolithic. During 4 th season of excavation, at Zone F, a pit with lithic tools and a deer fossil bone were discovered. All finds are included in late Pleistocene deposits, which were confirmed by Paleomagnetism and geological observations.
In 1999, during 5 th season, from Zone A, large amount of Jomon remains, including scratched or non decorated pottery fragments of the incipient Jomon, bone points, discs made of shell and so on were unearthed. At Zone F, lithics were concentrated within a small area and fossil bones of deer, Japanese serow and bear were found close to the concentration. Also fossil femur of wild boar, which is probably an extinct sp., was found there too.
Combining above-mentioned discoveries, it is supposed that some kind of ritual activities might have been conducted in the rear chamber. It is also stressed that we could accumulate informative data of Incipient Jomon too, due to good association of archaeological materials and fossil remains.