島原之亂
is a castle located in Minamishimabara, Nagasaki Prefecture, Japan. The castle was originally built in the 13th century. It belonged to the Arima clan, and was the residence of the Christian "daimyō". In 1637, during the Shimabara Rebellion, it was burned down by the forces of the Tokugawa Shogunate. The castle's ruins can still be seen.