OVERVIEW

Hara Castle is said to have been built by the feudal Lord Arima Takazumi in 1496. Its influence extended to the Eastern area of Hizen Domain (currently Saga Prefecture) and counted an income of 26,000 koku* . The castle spanned a 4 km² wide area, with three of its sides surrounded by the sea. Therefore, it was considered a naturally impregnable fortress. The castle was divided into 4 separate palaces: the main palace, the second, the third and the Amakusa palace. Due to its beautiful position it was also referred to as the “Sunset Castle.” Matsukura Shigemasa, the feudal Lord of Yamato Gojo Domain released the ikkoku ichijo rei (Law of One Castle per Province), so Moritake Castle (i.e. Shimabara Castle) was constructed, leading Hara Castle and Hinoe Castle to be abolished.
The site of Hara Castle is widely known as the place where the Shimabara-Amakusa Revolt happened (1637-1638). In May 30, 1938, it was designated as a National Historical Site.
*Koku: In feudal Japan, the incomes of samurai were measured in koku of rice. A koku of rice was considered to be the amount needed to feed one man for one year. To be a daimyo, a samurai needed an annual income of 10,000 or more koku; an income of 26,000 koku proofs how wealthy the Arima clan was.