Shimabara Castle was built by Matsukura Bungonokami Shigemasa over a period of seven years, beginning in 1618 (Genwa 4). It was a magnificent castle that adopted the castle construction style of the Azuchi-Momoyama period, with a five-story castle tower at its core and large and small turrets placed at key points.

However, when the Shimabara Rebellion broke out in 1637 (Kan'ei 14), farmers and Christians from the Shimabara Peninsula, who were dissatisfied with the rule of the Shimabara Domain, surrounded Shimabara Castle. Shimabara Castle fell after 50 days of fierce fighting, and the Matsukura clan was wiped out.

After the Meiji period, the castle was abandoned and the buildings were removed, and the castle tower, turrets, and long walls have now been reconstructed in the main citadel, and the castle ruins have become a castle park.

The castle tower was restored in 1964 using reinforced concrete.
Inside the castle tower are the Christian Museum, the Local History Museum, and the Folk Implement Museum, where you can learn about materials related to the Shimabara Rebellion, exhibits related to hidden Christians, and local history and cultural assets. From the observation deck on the top floor, you can enjoy a magnificent panoramic view of not only Shimabara city, but also the Ariake Sea and Kumamoto on the opposite shore.