01 / The Water Gate of Kakenouma Kōgoishi (鹿毛馬神籠石)
Under the rampart closing the valley mouth,two drainage culverts were built.

The valley mouth was closed with an earthen rampart about 60 m long and 9 m wide, and drainage culverts (underground channels) were built beneath it. Both culverts measure about 18 m in total length. Posts were found inside the rampart at intervals of about 3 m; they may also have stood above it as a fence.
- 2 culverts (about 18 m each)
- Rampart about 60 m long, 9 m wide
- Posts inside the rampart at about 3 m intervals
