There are many caves along Shimane Peninsula coast, and they are considered sea caves. Some of them were used by the ancient people for dwellings or other purposes, and remain as the archaeological sites. These cave sites are located facing the coastal line, so it is considered that the ancient people who used the cave sites were influenced by the sea level changes or other enviroumental changes. And for these reasons, researches of the cave sites contribute to not only archaeological studies but also palaeo-environmental studies and so on. With these aims, we planed the excavation of the cave sites, and carried out the research at Sarugahana Todai cave site, Mihonoseki town, Shimane prefecture, in 1995, 1996 and 1997 (Takehiro and Watanabe et al., 1996 ; Takehiro and Ege et al., 1997 ; Takehiro and Watanabe et al., 1998).
In 1998, we carried out the 2nd excavation of Sarugahana Todai cave site and the trial excavation of Location rock shelter, 15 m west of the cave site.
In the 2nd excavation of this cave site, we excavated about 2.5 m^2 range in the front of the cave site, and reached about 0.9 m above the sea level. As one of the result of this excavation, we could find occupied surface around 1.2-1 m above the sea level, which is thought to belong to the later part of the early stage of the Jomon period or the former part of the middle stage of it, ca. 5,500 - 4,500 uncal. y. B .P.. And these date of occupation at this cave site are one of the oldest example of occupation in the cave sites at Shimane Peninsula at present. We could get the important data to research the problem about the date of the Jomon marine transgression, and so on.
In the trial excavation of Location rock shelter, we excavated about 2 m^2 range at the inner part of rock shelter. We found the occupied surface at 1 m depth below the present surface. And we found the archaeological remains of the Jomon and Yayoi periods.