The Kuromaru (黒丸), or "Black Fortress", was a fortress of the Kanrei Shiba Takatsune located in Echizen Province (present-day Nittazuka, Fukui, Fukui Prefecture) in the Hokuriku region of Japan. It was attacked twice during the Nanboku-chō Wars of the 14th century, during which it was likely both built and destroyed. The following year, upon his enthronement, Emperor Go-Murakami ordered the late Nitta Yoshisada's brother, Wakiya Yoshisuke, to lead another attack on the fortress. This assault was successful, and ended in Shiba's surrender.