Hirado Castle (Hirado-jo) was built in 1707 by the daimyo Matsuura Takashi. The donjon was built on top of a small, rounded mountain. The castle supposedly had a structure heavily influenced by the Yamaga-ryu, whose school of war strategy was highly regarded. It fell into disrepair after government by the samurai class ended in the latter half of the 19th century. The present donjon was reconstructed in 1962. The beautiful three-tiered, five-storied donjon was built as if overlooking the ocean, and a large amount of information relating to the castle is exhibited inside.