Tanaka Castle, Japanese castle in Fujieda, Japan

Tanaka Castle is a fortress site in Fujieda, Japan, built around a circular design with three rings of water defenses that once protected the inner keep. The ruins now form a public park where paths follow the old earthwork lines.

The Imagawa clan built the fortress in 1537 to guard the western approaches to Sunpu. Takeda Shingen captured and remodelled it in 1570, and the three concentric moats date from Takeda rule. The Honda clan held it from 1730 until 1868, when they were moved to Awa Province; the castle was pulled down in 1872.

The surviving gate and relocated structures show how castle architecture evolved across different periods. Local residents now use the grounds as a quiet place for morning walks and weekend picnics.

The grounds are open daily except Mondays and the day after public holidays, from 9 AM to 5 PM with no entry fee. Paths cover flat terrain and are easy to walk for a short loop through the park.

Tanaka Castle had no keep: a two-story yagura stood at the southwest corner of the Honmaru instead. That tower was sold to the Yamamura family in 1870 and used as a house, given back by local residents in 1985, and moved to the castle residence site in 1996.