A castle from that lofty position would command a view of the plains below and would serve as a symbol of power in the region.

Renovations to the castle were done during the Kōji era (1555–1558), and the stone ramparts were enlarged to accommodate small cannons.

After capturing Mino Province, Nobunaga allied himself with the Azai clan and with the exiled Ashikaga Yoshiaki, with whom was determined to march on Kyoto.

[4] The Rokkaku, loyal to the Ashikaga shōgun, attempted to disrupt to Nobunaga's advance, but were soundly defeated by Niwa Nagahide.

Nothing remains of the castle today except for fragmentary ruins of stone walls, a stone-lined well, and a historical signboard.

Much of the secondary areas of the castle were recovered by Kannonshō-ji temple, which became a popular pilgrimage location in the Edo period.

The trail leads up the west side of the mountain, first to the ancient temple Kuwanomi-dera (桑実寺), then through a forest of Japanese cedars, and up to Kannonji Castle site.

The other leads up the eastern slope, and can be found near Route 202 off the Nakasendō Highway in the neighboring town of Gokashō.