- Type: Okinawan gusuku
- Founder: Itokazu anji
- Status: Ruins
- Japanese: 糸数城 (Itokazu gusuku)
Itokazu gusuku is the third-largest fortress on Okinawa Island, after Shuri castle and Nakijin castle, covering roughly 66,000 square meters. Located on a limestone hill in the eastern parts of the village of Tamagusuku, about 180 meters above sea level, it is believed to have been constructed by Itokazu anji, the third son of the lord of Tamagusuku who built Tamagusuku gusuku. In fact, the two fortresses are located quite close together, on the same tableland, and it is believed they worked in concert to govern the surrounding area. The year of the construction of the fortress, however, is unknown.
Pieces of ceramics, celadons, and other trade goods excavated at the site indicate an involvement with overseas trade, and hint at an early 14th century (Sanzan period) construction date for the fortress.
The gusuku walls, as high as six feet in some places, are often compared to a dancing dragon. A combination of nozura-zumi (piling up of uncut rock) and kiri-ishi-zumi (piling of cut rock) techniques were used in the construction of the walls. The grounds are organized into a number of curved enclosures, and are bounded to the west and south by a low wall of uncut stone, and to the north and east, by a high wall of cut stone. The main gate of the castle faces the east; the tombs of the lords of Itokazu, and a shrine, are located inside. A watchtower on the north side of the grounds, called Nishi-no-azana (北ぬ字), offers views of Naha, Shuri, the Kerama Islands, and Katsuren, while the south watchtower, called Fee-no-azana (南ぬ字), faces towards Tamagusuku, Gushichan, and the Pacific.
The fortress has been named a "national historic site" (国指定の史跡).
- Kitahara Shûichi. A Journey to the Ryukyu Gusuku 琉球城紀行。 Naha: Miura Creative, 2003. p59.