Takamatsu Castle

Overview

Takamatsu Castle (高松城, Takamatsu-jō) is a Japanese castle in central Takamatsu, the capital of Kagawa Prefecture on the island of Shikoku. Construction began in 1590, during the Azuchi–Momoyama period (1573–1603), in the eighteenth year of the Tenshō era (天正, Tenshō). The castle sits at the coordinates 34.3504° N, 134.0520° E, in the Tamamochō district of Takamatsu, within what is now Tamamo Park.

The castle served as the headquarters of the Takamatsu Domain, the feudal administration that governed eastern Sanuki Province — the area corresponding to modern Kagawa Prefecture — from 1588 to 1869. It is counted among the 100 Fine Castles of Japan, a list maintained to recognise the country's most historically and culturally significant castle sites.

Takamatsu Castle is also known as Tamamo Castle (玉藻城, Tamamo-jō), a name taken from its seawater moats. It is one of only three castles in Japan built with moats filled directly from the sea, alongside Imabari Castle in Ehime Prefecture and Nakatsu Castle in Ōita Prefecture.

History

The castle was founded in 1590, at the close of the Sengoku period, the century of civil war that ended with the unification of Japan under Toyotomi Hideyoshi and, after 1600, Tokugawa Ieyasu. Its construction belongs to the wave of castle-building that followed the political consolidation of the realm, when regional lords were reorganised and set to work fortifying strategic points.

From 1588 the site was the seat of the Takamatsu Domain, the feudal territory that administered eastern Sanuki Province. The domain's headquarters remained at Takamatsu Castle until 1869, the year after the Meiji Restoration began dismantling the domain system. Over those nearly three centuries the castle was both renovated and expanded, its defences and buildings adapted by successive generations of domain lords.

The defining engineering decision at Takamatsu was the use of seawater in the moats. The castle was built on the coast, and its outer ditches opened directly onto the sea, so that ships could enter and leave without passing through a lock or gate. This made the castle not only a defensive stronghold but a working port for the domain. The same approach was used at Imabari Castle and Nakatsu Castle, both of which also face the Inland Sea or its approaches.

What Stands There Today

The castle grounds are now Tamamo Park, a public park in central Takamatsu. The site has been designated a National Historic Site since 1955, a status that protects the surviving earthworks, moat lines and layout of the original castle.

The seawater moats remain the most distinctive feature of the site. Because they are fed by the tide rather than by rivers or springs, the water level rises and falls with the sea, and the moat walls carry the marks of that daily cycle. The park preserves the footprint of the castle's baileys and ditches, and visitors can trace the extent of the original fortification through the surviving water channels and stonework.

The Name in Japanese

The castle's name in Japanese is 高松城. It is read たかまつじょう in kana, and written Takamatsu-jō in romanised form. The alternative name is 玉藻城, read たまもじょう, Tamamo-jō.

Breaking 高松城 down character by character:

• 高 — read here as taka. It means "high" or "tall." It is the same character used in words like 高校 (kōkō, high school) and 高い (takai, expensive or tall).
• 松 — read here as matsu. It means "pine tree." Pines are a standard motif in Japanese place names and castle names, and the character appears in many of them.
• 城 — read here as jō. It means "castle." On its own the character can also be read shiro, which is the native Japanese word for a castle. In compound names of castles, the Sino-Japanese reading jō is standard: 大阪城 (Ōsaka-jō), 姫路城 (Himeji-jō), 熊本城 (Kumamoto-jō).

So 高松城 means, literally, "High Pine Castle." The first two characters, 高松, are also the name of the city — Takamatsu — which is written with the same two kanji and read the same way. The castle name is simply the city name plus 城.

The alternative name 玉藻城 breaks down differently:

• 玉 — read here as tama. It means "jewel" or "gem," and by extension something beautiful or precious.
• 藻 — read here as mo. It means "seaweed" or "waterweed."
• 城 — again read jō, "castle."

玉藻 therefore means something like "jewel-like seaweed," a poetic image for the clear water and marine plant life of the moats. The name Tamamo-jō, "Seaweed Castle," is a direct reference to the castle's saltwater defences, and it is the name most often used in local speech and in the park's own signage.

Visiting and Context

Tamamo Park occupies the castle site in the Tamamochō district of central Takamatsu, a short distance from Takamatsu Station and the city's port. The park is the principal public access point to the castle remains, and the seawater moats are visible from its paths and bridges.

For readers studying Japanese, Takamatsu Castle offers a compact lesson in how castle names are built. The pattern is consistent: a place name, usually two characters, followed by 城 read as jō. Recognising 城 in a compound is one of the fastest ways to identify a castle name in Japanese text, and the shiro reading appears whenever the word stands alone. The alternative name 玉藻城 adds a second layer, showing how a descriptive nickname can attach itself to a site and, in this case, outlive the formal name in everyday use.