石山本願寺
was a series of fortresses and fortifications controlled by the Ikkō-ikki, a sect of warrior monks in Japan's Sengoku period who opposed samurai rule. It was attacked and destroyed by Oda Nobunaga in the 1570s. This, combined with the surrender of the Ikki's other main fortress, Ishiyama Hongan-ji, several years later, ended the threat the Ikko-ikki posed to Nobunaga and other "samurai" conquerors.