Saitama Prefectural Ranzan Historical Museum is located within a nationally designated historic site ”Sugaya Yakata Castle”. Through the current state of the remains of a castle from Sengoku period, visitors can envision the foundation of the medieval castle by seeing materials such as earthworks and the moat. It is also traditionally known as the site of the palace of Kamakura period samurai Hatakeyama Shigetada, 300 years before Sengoku period.

Sugaya Yakata Castle 

1 The medieval residence and castle
2 Hatakeyama Shigetada and other samurai of Musashi 
3 Medieval stonework including” itabi” (buddhist stele), ”gorintō"（five elements stupa）, and ”hōkyōintō"（small memorial square tower topped with a spire）
4 Medieval temple and temple remains
5 Medieval roads such as the Upper Kamakura Road (Kamitsumichi)

The exhibits, lectures, and research all cover the medieval period (from the end of the Heian period to the end of Sengoku period).

 These are the ruins of Sugaya Castle, which is said to have been the residence of HATAKEYAMA Shigetada (1164-1205), a powerful local lord, at the end of the 12th century.

HATAKEYAMA Shigetada was born in what is now the Hatakeyama district of Fukaya City in Saitama Prefecture. His father was HATAKEYAMA Shigeyoshi, a powerful local lord, and his mother was the daughter of MIURA Yoshiaki, a powerful lord of Sagami Province (the western part of modern-day Kanagawa Prefecture).

The HATAKEYAMA Clan was originally aligned with the Taira Clan, but switched allegiance to MINAMOTO no Yoritomo in 1180 when Yoritomo raised an army against the Taira. Shigetada fought in numerous battles and played a contributing role in the establishment of the Kamakura Shogunate. He continued to support the Kamakura Shogunate following Yoritomo’s death, but became entangled in a power struggle within the Shogunate in 1205 and met a violent end that year in what is now the Futamatagawa district of Asahi Ward, Yokohama City.

Following the Kyotoku Incident (a series of conflicts fought for control of the Kanto region) in 1454, Kita-Musashi (a region in present-day Saitama Prefecture) entered Sengoku Period (1454-1590). The Hiki region where this museum is located has more than 60 confirmed medieval castle ruins, the majority of which were constructed in the late 15th and 16th centuries.

Of these, in addition to the Sugaya Castle Ruins—the site of the museum—the Sugiyama Castle Ruins (Ranzan Town), Ogura Castle Ruins (Tokigawa Town), and Matsuyama Castle Ruins (Yoshimi Town) are especially well preserved, and their ruins provide a good understanding of the structure of Warring States Period castles in the Kita-Musashi region. For this reason, together as the “Hiki-jo Castle Ruins” these four castle sites were as designated national historic sites in March 2008.

Once the residence of warlord HATAKEYAMA Shigetada, Sugaya Yakata Castle Ruins was a plains-type castle (built on a low hill surrounded by plains) and was expanded and restructured during Sengoku Period.

Niju Dorui (Double Clay Walls)

Sugaya-Yakata Castle was separated from the outside by a wide belt of low-lying land. The land was created naturally by a valley, which is currently located under Route254. There was a low outer clay wall and moat facing the valley and a higherclay wall inside the lower one. These double clay walls protected the castle.

 Kuichigai-Koguchi Entrance (Attributed tothe Site of the karametemon Gate)

An entrance to a castle or an entrance to a bailey is called koguchi. The entrance to Sugaya-YakataCastle is a kuichigai-koguchi(unparallel) entrance created by making a three-meter gap between the edges ofthe inner wall of the double clay walls to guard against invaders from the outside.An earth-paved bridge was built in front of this gate to provide a path tooutside the castle. The bridge is still used as an entranceway.

Sannokuruwa (Third Bailey)

Through the kuichigai-koguchi gate on the northern side of the castle site, there is a flat land area whichextends from east to west. This has been called the Sannokuruwa (third bailey) since the late Edo period. Judging fromits size and location, it was most likely used as a meeting place for samuraiwarriors and horsemen.

Shitomi Dorui (Clay Wall to disturb the prospect of the enemies )

There is a small clay wall inside the entrance, facing the moat. The purpose of this wall was to make it difficult to see the Sannokuruwa(third bailey) from the Nishinokuruwa(west bailey). Taking the name from shitomi(latticed shutters) that were used in residences during the Heian period (794–1185) to keep out sunlight, rain and wind, the clay wall that blocks the view from the outside is called a shitomi dorui.

Shotenmon Site and Wooden Bridge

The west entrance of Sannokuruwa(third bailey) is approximately nine meters (29.53 feet) wide and has been called a Shotenmon since the Edo period.An excavation found that the area had an embankment that was one meter (3.28feet) higher than that of the Nishinokuruwa(west bailey). 
A masonry structure that is believed to have been the foundation for the piers of a wooden bridge, was found in the moat between the Shotenmon and Nishinokuruwa. Based on these findings, a wooden bridge once stood there.By building a higher sloped embankment, they were guarding against invaders from the outside. A bridge was built based on the research findings, but the actual structure of the wooden bridge is unknown.

Ninokuruwa (Second Bailey)

There is a flat land mass surrounding the Honkuruwa(main bailey) from west to north. This area has been called a Ninokuruwa since the Edo period. It is separated from the Sannokuruwa by asix-meter (19.68 feet) clay wall and moat. A walkway is now situated where the moat was located. The area which is currently covered by plants is thought tohave been the location of a clay wall.

Demasugata Dorui (Protruding Square ClayWall)

The tall wall was there to guard the Honkuruwa(main bailey), and there is a section protruding from it. This shape is called a Demasugata. This protruding square wall was used to effectively guard against invaders. Arrows could be shot from the side.

Minamikuruwa (South Bailey)
On top of the cliff, at the south edge of the castle site and facing the TokigawaRiver, there is a thin strip of flat land from east to west. This area is called the Minamikuruwa (southbailey). The Minamikuruwa was built lower than the other baileys. The main purpose of this bailey is unknown.

Honkuruwa (Main Bailey)

This flat land mass in the middle of many layers of moats, clay walls and baileys in the castle site has been called a Honkuruwasince the Edo period. It is thought that the main building of the castle was located here.

BuildingSite and Well Site

At the excavation prior to the building of the Museum, four dug-standing pillar buildings, three well and some ditches were found. Among these remains, the locations of a building and well are shown.