As was typical for the time, the fortifications consisted primarily of wooden palisades and earthen ramparts, guarded by 20-meter wide dry moats.

There was no donjon in the central bailey, which was occupied by a large building, possibly in the Shōin style, based on evidence of foundation posts, as the residence of the ruling Nanbu clan.

Ne Castle was constructed in 1334, during the early Nanboku-chō period, by Nanbu Moroyuki, a retainer of Kitabatake Akiie, the kokushi of Mutsu Province and was intended to be a center for the imperial government administration in the area.

In 1627, the 22nd generation castellan, Nanbu Naohide was relocated to Tōno in what is now Iwate Prefecture and Ne Castle was completely abandoned.

From 1983 to 1994, extensive archaeological investigations uncovered the foundations of the original structures and many artifacts from the Namboku-chō period.