- Type: Flatland-Mountain
- Built: 1602-1606, Shimazu Iehisa
- Destroyed: 1874
- Location: Kagoshima, Satsuma province
- Other Names: 鹿児島城 (Kagoshima-jou)
- Japanese: 鶴丸城 (Tsurumaru-jou)
Tsurumaru castle, also known as Kagoshima castle, was the chief castle of the Shimazu clan of Satsuma han. It sat up against Mt. Shiroyama, facing out towards the castle town, beyond which lay the sea.
The castle was first established by Shimazu Iehisa as an expansion of Ueyama castle (built by the Ueyama clan in the 14th century). It is said that Shimazu Yoshihiro opposed the idea of having the domain's chief castle be so close to the sea, but his son Shimazu Tadatsune desired to use this site as the political center of the domain. The complex came to be known as Tsurumaru ("crane bailey") castle as it was said to resemble a crane with its wings outstretched.
The castle was distinctive for its lack of a tenshu or tower keep, and was constructed in a style known as yakata-zukuri, combining some of the defensive elements of a castle with the architectural layout of a residential mansion. While most castles elsewhere in the realm had more extensive architectural defenses, Satsuma had a rather high proportion of gôshi (rural samurai), and the lords of Kagoshima said "the people are the stronghold." No map or diagram of the layout of the interior is known to survive, but the main audience hall is known to have been a room decorated with paintings of tigers and called the Tora-no-ma ("Tiger Room"). The castle is also known to have maintained an abbreviated Noh stage. The Shimazu had professional Noh actors in their service throughout the Edo period. Noh dances or plays were frequently performed at the castle, both by these professional actors, and at times by the Shimazu lords themselves as well.
The honmaru (central bailey), which housed the lord's residence, and offices of domain administration, burned down in 1873. The ninomaru (second bailey), where the residences of retired lords and the lord's heir were located, was destroyed by the Imperial Japanese Army on 1877/9/24, the final day of the Satsuma Rebellion.
The castle grounds were taken over by the Meiji government for official use in the Meiji period, and then from 1901 until 1950 was home to the 7th High School Zôshikan; the iron gates of the school remain the main gates to the grounds today. The Iso Palace at Sengan'en, previously a secondary or vacation palace, then became the chief residence of the Shimazu clan.
Today, the Reimeikan Museum of History and Culture (est. 1983) occupies the former honmaru of the former castle grounds, while the Kagoshima Prefectural Library sits in the former ninomaru area. A number of historical remnants, and commemorative monuments also stand on the site. The stone Ôtebashi, originally completed in 1606 remains intact as the main bridge over the moat. While the Ôtemon tower gate (gorômon or o-yagura mon) to which it used to lead burned down in a fire in 1873, it was reconstructed in 2019. The masugata stone foundations, forming a right-angled entry into the castle grounds, for defensive purposes, and some remains of the corner tower (kado yagura), and of the Kirin-no-ma of the honmaru palace, which also burned down at that time also survive.
A statue of Atsuhime, designed by Order of Culture winner Nakamura Shin'ya, was erected on the grounds in 2010. Another set of statues on the grounds depicts students from the 7th High School, and is accompanied by other monuments and markers related to the school. A stone dedicated to Lord Shimazu Shigehide, who founded the Zôshikan han school in 1773, was erected in 1942. Another stone marker associated with Shigehide commemorates the treasure house, known as the Shûchinhôko, which he maintained at the Shimazu clan's Edo mansion at Takanawa. There, he kept rare plants and animals, local products from various places across Japan and overseas, and conducted efforts in classification and research. This stone was moved to Kagoshima in 2000 from the former site of the Edo mansion, in Yukigaya, Ôta-ku, Tokyo. Another stone, erected in 1912, commemorates the visit of the Meiji Emperor to Kagoshima on imperial tour in 1872.
Finally, one of the ponds of the castle's gardens, in the southeast corner of the grounds, has been recreated.
- Explanatory plaques on-site at Shiroyama.
- Gallery labels, permanent exhibition, Reimeikan Museum, Kagoshima, Sept 2014.
- Iwahana Yuki 岩花由貴, “Kagoshima ni okeru Ryūkyū shisetsu no girei ni tsuite” 「鹿児島における琉球使節の儀礼について」, Kamiya Nobuyuki (ed.), Kinsei Nihon ni okeru gaikoku shisetsu to shakai henyō 3: taikun gaikō kaitai o ou 近世日本における外国使節と社会変容３－大君外交解体を追う－, Tokyo: Waseda University Kamiya Nobuyuki kenkyūshitsu (2009), 67.
- Iwahana, 69-71.
- "Tsurumaru-jô ninomaru ato," plaque on-site at the former castle grounds.
- Gallery labels, permanent exhibits, Shôkoshûseikan, Kagoshima, Sept 2014.