A castle located on Mount Shigi, controlled by the Kizawa and Matsunaga clans. It was constructed in 1536 by Kizawa Nagamasa, who commanded it on behalf of the Hatakeyama Clan, then repaired and expanded by Matsunaga Hisahide, who commanded it on behalf of the Miyoshi Clan.

The castle was destroyed by Oda Nobunaga in the Siege of Shigisan in 1577, in which Matsunaga Hisahide was killed.