About 40 mounded tombs (kofun) were located in Jinseki-kōgen chō, Hiroshima Prefecture.These tombs had corridor-style stone chambers with both sides of the corridor directly in line with the chamber’s lateral walls (musodegata yokoana sekishitsu) that were built during the Late Kofun period (the second half of 6th century to the middle third of 7th century A.D.). However, no detailed information about them was available to the public at al. The Sarugababa mounded tomb No. 1 is one of the few remaining musodegata corridor-style stone chambers in Jinseki-kōgen chō.
The Department of Archaeology at Hiroshima University conducted a field survey of the Sarugababa mounded tombs No. 1 and No. 2, the surrounding topography, and Sue ware (sueki), that was believed to have been unearthed from the Sarugababa mounded tomb group (kofun gun). Considering the change of musodegata corridor-style stone chambers in the Bingo region (the eastern part of Hiroshima Prefecture), Sarugababa mounded tomb No. 1 was built during the TK209-TK217 phase (end of the 6th century to the first half of the 7th century A.D.). However, most of the Sue ware was found to be unearthed from the mounded tomb group, which is slightly older than mounded tomb No. 1. The other mounded tomb groups are thought to have been built before mounded tomb No. 1. Additionally, a field survey was conducted on the mountain ridges around the Sarugababa mounded tomb group. It became clear, however, that all the tombs targeted in the field survey had vanished or were destroyed. The Nakayama-Yotuzuka mounded tomb group was one of those that disappeared. Nevertheless, objects (horse bits and stirrups) are now in the possession of the Hiroshima Prefectural Museum of History. Like the Takafuta-Tsukatani mounded tomb, horse bits with gourd-shaped iron cheek rings (hisagogata kanjō kagami itatsuki kutsuwa) are distinctive features of mounded tombs in the Kibi region (ancient province consisting of Okayama Prefecture and the eastern part of Hiroshima Prefecture).