Tamanawa Castle

Overview

Tamanawa Castle (玉縄城, Tamanawa-jō) is a ruined castle site in the Tamanawa district of Kamakura, in Kanagawa Prefecture, south of Tokyo. It was founded in 1512, the ninth year of the Eishō era (永正, えいしょう), during the Muromachi period (1336–1573). The castle is closely associated with Hōjō Tsunashige, the adopted brother of Hōjō Ujiyasu, who served as its commander. Tamanawa Domain took its name from the castle, and the site is now preserved as castle ruins.

History

Tamanawa Castle was built in 1512, in the late Muromachi period, when eastern Japan was dominated by the Hōjō clan of Odawara. The castle guarded the western approach to Kamakura, the city that had been the seat of the shogunate from 1185 until 1333 and remained the region's most important religious and symbolic centre. Its position on the edge of the Kamakura hills gave it control over the routes into the city from the west.

The commander most closely tied to the castle is Hōjō Tsunashige, the adopted brother of Hōjō Ujiyasu. Ujiyasu was the third head of the Odawara Hōjō, the daimyo house that ruled the Kantō region through much of the sixteenth century. Placing an adopted brother in command of Tamanawa kept a trusted member of the family in charge of a frontier stronghold facing Kamakura.

The castle gave its name to Tamanawa Domain, the administrative territory attached to it. Hōjō Tsunashige is recorded as having died at the castle, which tied the site permanently to his name in the historical record.

What Stands There Today

Tamanawa Castle survives as castle ruins rather than as a standing fortress. The site lies within present-day Kamakura, in the Tamanawa ward, and is identified in modern records as a castle ruin of the Muromachi period. Earthworks and the layout of the fortified ground are what remain of the sixteenth-century structure; no keep or main building survives above ground.

The Name in Japanese

The castle's name is written 玉縄城. Its kana reading is たまなわじょう, and its romaji is Tamanawa-jō.

The name breaks down into three characters:

• 玉 — read たま (tama) here. The character means "jewel" or "gem"; in older usage it also meant "ball" or "sphere." As the first element of a place name it is common and carries a sense of something precious or rounded.
• 縄 — read なわ (nawa) here. The character means "rope" or "cord." In place names it often refers to a measured or marked-out piece of land, from the old practice of laying rope to measure boundaries.
• 城 — read じょう (jō) here. The character means "castle" or "fortress." It is the standard suffix for a Japanese castle name, so Tamanawa-jō is simply "Tamanawa Castle."

Together, 玉縄 (Tamanawa) is the place name and 城 (jō) marks the structure. The reading じょう is the Sino-Japanese one; the native Japanese reading of 城 is しろ (shiro), which is also used for castles in everyday speech. Learners will meet both: 城 (しろ) in conversation and 〜城 (〜じょう) in formal names such as this one.

Visiting and Context

Tamanawa Castle lies in the Tamanawa area of Kamakura, in Kanagawa Prefecture, at coordinates roughly 35.35° north and 139.52° east. It sits within the wider Kamakura region, which is easily reached from Tokyo and is one of Japan's best-known historic destinations.

For readers studying Japanese, the castle is a useful entry point into the vocabulary of the Muromachi period. The era name Eishō (永正, えいしょう) appears in dates from 1504 to 1521, so a foundation date of "Eishō 9" corresponds to 1512. The title jō (城) recurs in castle names across the country, and the pattern of a Hōjō family member holding a frontier castle illustrates how the Odawara Hōjō extended control across the Kantō region in the sixteenth century. The site itself is a ruin, so a visit is a walk through earthworks and place names rather than a tour of standing buildings — best paired with the better-preserved sites and temples elsewhere in Kamakura.