Where best preserved, the buried stone wall survived to a height of about 4 m. The wall was basically built as uncoursed masonry, with stone blocks piled in diagonal orientation, but near the corner this changes to coursed masonry, with the tops of the blocks forming horizontal lines. The care with which it was constructed became evident in such details as the fixing of corner stones in place with iron dowels on their upper and lower sides, and backing them with a double layer of large stones.

In the 2011 fiscal year the tonsho was investigated, and glazed pottery from the end of the Edo period, plus two Minié balls were found. In fiscal 2012 the eastern outer side was excavated, and conditions were learned of the reclamation, stone wall, and underwater areas.

Features identified as facilities of the battery's interior, such as a stone-lined drainage gutter, embankment, and earthwork, were discovered during investigation near the entrance. The building's base was supported with sturdy construction, using foundation piles with a ground sill.

It was learned that great volumes of hardpan were laid down approximately 24 m seaward, upon which rough stones unsuited for other construction were piled in the large-scale reclamation for building the artificial islands of the batteries. It is thought that the wooden framework of piles seen to the front was first set up, and then used as a base for starting the reclamation work.

In the same manner as for the tonsho, a construction technique adapted to weak ground was used for the stone wall, with a ground sill made as a framework of crossed horizontal members.

In the initial plan there were to be 11 placements set up, but construction began at just eight, of which six were completed. At present only Nos. 3 and 6, directly below the Rainbow bridge, are preserved as a Historic Site.