This was the largest branch castle of the Odawara Hojo family, and was built by Hojo Ujiteru around 1582 to 1587. The ruins are considered extremely valuable because the age of the excavated remains and artifacts can be identified, as the castle fell less than 10 years after it was built. The ruins retain the appearance of a mountain castle including the stone walls from the end of the Sengoku period (Warring States period; 1467–1568), while the lord’s residence and old roads have been restored, providing the experience of setting foot in a mountain castle of the time. At the foot of the mountain is the Hachioji Castle Ruins Guidance Facility, which provides the opportunity to wear armor and learn about the history of the Hojo family and the castle (one of Japan’s top 100 castles).