Nirayama Castle
During the Age of Civil Wars (1232-1603), Ise Sozui (commonly called Hojo Soun) built the Nirayama Castle on a hill of Nirayama.
Soun built and maintained this Nirayama Castle in order to subjugate the warriors who were enemies of Minamoto-no-Yoritomo and gained hegemony over the whole of Izu.
Since then he has died here as a lifelong resident.
Excavation is still ongoing as a historic site of the Age of Civil Wars in Japan.