Excavations at Dainichiyama Mound 35

Abstract

Located on the left bank of the lower reaches of the Kinokawa River in northern Wakayama Prefecture, Dainichiyama Mound 35 is part of the nationally-designated Iwase Senzuka kofun cluster that extends over the Iwase mountains. From its size and location, this mound had traditionally been seen as one of the main kofun of the cluster. Although the mound is preserved in a designated locality, many details remain unclear from previous research, which includes the plans of the mound and stone chamber and the haniwa surface collection made by Kansai University.
With the aim of preserving and utilizing the kofun cluster, from Heisei 15 Wakayama Prefecture began preservation and repair work at the Iwase Senzuka kofun cluster national historical site, and excavations were conducted at Dainichiyama Mound 35 as part of this work. These excavations clarified various aspects of the mound, including the structure of the central burial and outer mound, the mound size, and its shape. It was also shown that there were projections on the east-west constriction. Excavations on the eastern projection found many haniwa and Sue ware placed in an area surrounded by a row of circular haniwa. Analysis of artifacts during fiscal Heisei 16 confirmed representational haniwa including houses, lids, swords, human figures, birds and horses. Sue vessel forms included kame pots, pedestalled takatsuki, and stands. The representational haniwa include a gliding bird, a bird with a long beak that is probably a crane, a horse haniwa mud guard with armor slats, and the hip roof of a house with pillars sup-porting the ridgepole beam. These types of haniwa are extremely rare, with few similar examples in western Japan. Moreover, this is the first example of a bird-shaped haniwa depicting flight.
The excavations demonstrated that the mound has three levels, but it is not certain if these are three step-like con-struction levels or whether the bottom level should be seen as a foundation platform associated with the mound. There are many points which await further excavation, but the author tends to support the second interpretation based on the currently available evidence. A comparison of tombs of the same age in the Iwase Senzuka cluster with the recently-excavated Imashirozuka kofun is used to support this interpretation and related problems are also discussed.
Dainichiyama Mound 35 may be the largest keyhole-shaped tomb in the Iwase Senzuka kofun cluster, which dates from the first half of the 6th century. The haniwa cluster on the projections is of a quality and quantity that is noteworthy even in western Japan. Further excavations and analysis may well change the picture of Dainichiyama Mound 35 presented in this paper, contributing further to research on Kofun tomb rituals and the local history of the Wakayama region.