The castle is located on a hill named Kasagakeyama three kilometers west from Odawara Castle, which overlooked all of the Odawara's defenses. Although intended from the start as a temporary fortification, it was built with massive stone walls and a tenshu central keep. Hideyoshi was noted as both a master castle builder and a master of psychological warfare. It was constructed in secret in a wooded area over an 80 day period, so that when the trees were cut one night, the castle suddenly appeared. To the Hōjō defenders, it looked like the castle was built in just one night, which resulted in demoralization and a loss in the will to continue resistance against the Toyotomi army. As a result, only nine days later Hōjō clan formally surrendered.[6][5] Afterwards, the castle was abandoned, and soon fell into ruins.[6][5]
