- Destroyed: 1477
- Status: Excavations only
- Japanese: 石神井城 (Shakujii-jou)
Shakujii castle was a major power base of the Toshima clan in the south of Musashi province, from the Kamakura period through the beginning of the Sengoku period. Though the location, inside what is today Shakujii Park, in Tokyo's Nerima-ku, is known, little of the castle survives to be seen today.
It is not clear when the castle was first built, however, the Toshima clan held power over this region from the end of the Heian period until the 1470s. The castle, defended primarily by earthworks, and not the distinctive stone foundations of Azuchi-Momoyama period castles, lay a short distance from Sanbôji pond. Earthworks and dry moats defended it on three sides, while a natural cliff served to protect it from attack in the direction of the pond.
An alliance in 1476 between Toshima Yasutune, lord of the castle at the time, and Nagao Kageharu led to the castle's destruction the following year at the hands of Ôta Dôkan, a retainer of the Ogigayatsu Uesugi clan, enemies of the Nagao clan.
- Explanatory signs on site.
- "Shakujii-jô." Uzumoreta kojô: Kantô chihô no shiro. Accessed 17 December 2009.