- Japanese: 安慶名城 (Agena-jou / Agena gusuku)
- Other Names: 大川城 (Ookawa-jou / Ookawa gusuku)
- Type: Okinawan gusuku
- Founder: Ôkawa anji
- Status: Ruins
- Year: 14th century
Agena gusuku was an Okinawan castle which is believed to have been built by the anji (lord) of Ôkawa, in the 14th century. It lasted only three generations, being passed down to the son and grandson of its founder.
The castle made good use of the natural topography, being located on a mountain or hillside roughly 49 meters above sea level, and bounded to the north by the Tengan river. It was organized in the rinkaku manner, with roughly concentric sets of walls forming separate baileys, the innermost surrounding an open space at the top of the hill, and the outermost located roughly halfway up the incline. The walls were made from piled-up cut stone, ranging in height from two meters to more than 10 meters at the tallest point.
The site is today a public park and nationally designated historical landmark in the city of Gushikawa.
- "Agenajôseki." Okinawa Konpakuto Jiten (沖縄コンパクト事典, "Okinawa Compact Encyclopedia"). Ryukyu Shimpo. 1 March 2003. Accessed 25 May 2010.
- Kadekawa, Manabu. "Agena-jô-seki." Okinawa Chanpurû Jiten (沖縄チャンプルー事典, "Okinawa Champloo Encyclopedia"). Tokyo: Yamatokei Publishers, 2003. p108.
- Kitahara Shûichi. A Journey to the Ryukyu Gusuku 琉球城紀行。 Naha: Miura Creative, 2003. p97.