Japan Castle Explorer: Mariko Castle -Genuine clay fortress guarded the valley-

Mariko Castle

-Genuine clay fortress guarded the valley-

Overview

Name: Mariko castle (Mariko-jo)
Alias: Utsunoya-jo (Utsunoya castle)
Place: Mariko Suruga-ku Shizuoka city, Shizuoka
Type: Mountain Castle
Built: 15th century
Remaining remnants: Clay walls and dry moats
Title:

Brief History

Mariko castle (丸子城) is located at a Mikadoyama hill, a one of 150 meter height thrusts into Mariko area at the west part of Shizuoka city. Mariko area is a narrow valley spreads east and west direction, and Tokaido road, a main route connected Tokyo city and Kyoto city runs through this area from Shizuoka city to Fujieda area, across Utsunoya Toge pass. In Edo era Mariko town became one of the 53 posting towns of Tokaido road, and a restaurant serves grated yam established in 17th century still operates here.

Build and expansion of castle

West end of Shizuoka city is covered by mountains, and travelers had to pass these mountain by any path. Originally Tokaido road passed at Nihonzaka area near the Pacific ocean (route of Shinkansen train and Tomei Expressway), but later the route changed to current style passes Utsunoya Toge path and Mariko area. Slope of current route is tighter than old route, but distance of mountainous road is shorter and the traffic was more stable.

Shizuoka city was formerly called as Sunpu city, and had been the capital of Imagawa clan. Precise year is unknown but Mariko castle was originally built by Imagawa clan in 15th century. At the beginning of 16th century, Mariko castle was managed by Saito clan, a local lord under Imagawa clan as a west gate of Sunpu city.

In 1568, Shingen Takeda (1521-1573), the warlord of Kai province (Yamanashi prefecture), broke the treaty with Imagawa clan and intruded Suruga province from northward. After struggle with Hojo army which supported Imagawa clan, Shingen occupied whole Suruga province (middle part of Shizuoka prefecture) including Sunpu city next year.

Takeda clan made a total reform to Mariko castle, to strengthen this castle as a fortress. Suruga province was managed by Masakage Yamagata (1529-1575), one of four brave generals of Takeda clan, and Mariko castle might be managed by the retainer of Masakage.

Structure of clay fortress

Mariko castle spread a jackknife shaped ridge continues from east to southwest over 300 meter. East half of the ridge is the old part built by Imagawa clan, then terraces are narrow and there seems no secure defense facility at this side. On the other hand, southwestern half of the ridge which directly faced the valley is newly extended area by Takeda clan. Compared with eastern half, terraces were wide and securely guarded by tall clay wall, deep dry moats and folding gates.

Especially this northwestern side of this area which faced the valley was guarded by two layer of long horizontal dry moat like trench. At the both end and middle of this horizontal dry moat a small fort was built, to command defense side soldiers and shoot enemy soldier from upper area. This type of horizontal dry moat along with the ridge is also seen at Takatenjin castle which was renovated by Takeda clan, but the depth of the moat and height of the clay wall is more strict at this castle.

As the west end of the castle is connected to a moderate slope and expected to be the target of enemy, a large semicircular shaped fort guarded by steep wall and deep crescent shaped dry moat were built to guard this side. At the east end of the castle where was the entrance to the castle, a deep crescent shaped dry moat was also attached to guard the entrance. At the both side of this edge two line of vertical dry moat was digged, to prevent side movement of enemy soldiers.

Afterward of castle

After the death of Shingen in 1573, his successor Katsuyori Takeda (1546-1582) fought against central ruler Nobunaga Oda (1534-1582) and his ally Ieyasu Tokugawa (1543-1616) at Nagashino in 1575, but suffered fatal defeat and Masakage Yamagata died in the battle. Ieyasu Tokugawa started counter attack to Takeda clan and recovered deprived part of Totomi province (west part of Shizuoka prefecture).

Border of both clan moved to Oigawa river, the natural border of Suruga province and Totomi province. Tokugawa army occasionally intruded into Suruga province, but Takeda army at Suruga province well protected Tanaka castle (Shizuoka prefecture) and Mariko castle then did not allow Tokugawa army to enter Sunpu city.

But in 1582, when Nobunaga started total attack toward Takeda clan, Baisetsu Anayama (1541-1582), a cousin in law of Katsuyori and the commander of Suruga province, turned to Ieyasu Tokugawa and left the province including Sunpu city and Mariko castle to Ieyasu.

Ieyasu placed his retainer Kiyoyoshi Matsudaira (1505-1587, called as Bingonokami) as a commander of Mariko castle, but in 1590 Tokugawa clan was transferred to Kanto region by Toyotomi government and Mariko castle might be abolished then.

Now all buildings were lost but clay structure of the castle satisfactory remains on the hill. Combination of deep dry moat, steep clay wall and tall fort seems powerful and is worth for visiting.