Sugiyama Castle (杉山城 Sugiyama-jō) was a hilltop castle located in modern-day Ranzan, Saitama Prefecture. Constructed on a mountain ridge at the edge of the Kantō plain it was overlooking the old Kamakura Highway, the modern-day Kanetsu Expressway. Making perfect use of the steep topography more than ten enclosures consisting of dry moats and clay walls were built across an area of eight hectares.
The designers of the castle used elaborate earthworks and moats as well as sophisticated construction techniques such as yokoya-kakari (横矢掛かり or 横矢掛り), structures that allowed defenders to attack the enemy from the side, and byōbu-ori (屏風折), castle walls that zigzag back and forth like a multi-panelled folding screen. These techniques gave the defenders a broader field of view to mounting crossfire counter-attacks from within the castle. Sugiyama Castle is considered one of the masterpieces of Sengoku castles.
The year of construction and the builder of the castle are unknown. The Hōjō clan, as well as the Ogigayatsu Uesugi and the Yamanouchi Uesugi, were mentioned as potential candidates, but recent excavations suggest that the Ogigayatsu Uesugi may have been used the castle in their conflicts with the Yamanouchi clan in the 15th century. A certain Sugiyama Mondo, a vassal of the Ueda clan of Matsuyama Castle, is said to have been in charge of this castle. Earthenware vessels and ceramics of the period between the end of 15th century and the mid of 16th century were excavated from the castle site.
Sugiyama Castle has been designated a National Historic Site in 2008 and was added to the "Additional 100 Finest Japanese Castles" (続日本100名城 Zoku Nihon hyaku meijō) in April 2017.
I parked my car near Shakuzenji temple just southeast of the castle grounds. That was the view onto the hill of Sugiyama Castle.
I took a devious route on the eastern side of the temple and climbed the hill.
The complicated configuration of the castle was immediately apparent; as it is difficult to understand the structure on the photos, I added some explanations to the images below.
Below the main entrance.
Enemies attacking frontally were forced to take a 90-degree left turn (red arrow). The defender could not only attack from the front but also from the earthwork (blue circle). This structure is called yokoya-kakari (literally a structure to shoot arrows from the side).
Another example of yokoya-kakari
Enemies attacking from left or right had to turn 90 degrees and then faced the front. They could then be attacked from the left-hand earthwork.
The main gate could be reached over a wooden bridge.
Notches on the edge of moats enabled the defenders to launch multidirectional attacks.
This structure is called "byobu-ori", literally fold of the screen.
Remnants of a well
One of the entrances to the main enclosure. Attackers had to turn right just in front of the entrance.
The well-kept inner bailey.
The enclosure near the grove led to the northwestern side of the castle.
This was the view from the northeastern side of the castle; in the distance the lush green hills of Hiki.
Date of visit: June 23, 2013