Kinojo Castle

Kinojo Castle, located in Soja City in Okayama Prefecture, stands as one of Japan's most impressive ancient mountain fortresses. Built during the 7th century, this kokyo or "ancient mountain castle" represents a crucial period in Japanese defensive architecture. The fortress was constructed on 400-meter-high Mount Kinojo as part of Japan's coastal defense system following the Battle of Baekgang in 663 AD, when Japan feared invasion from the Korean peninsula and Tang China.

The castle covers an enormous area of approximately 30 hectares, making it one of the largest ancient fortifications in western Japan. Its most distinctive features include massive stone walls that stretch for over 2.8 kilometers around the mountain's ridges, some sections rising 6 meters high. The fortress incorporated natural cliff faces into its defensive perimeter, demonstrating sophisticated military engineering. Archaeological evidence suggests the castle was equipped with multiple gates, watchtowers, and storage facilities, though much of the original wooden superstructure has long since disappeared.

Visitors to Kinojo Castle can explore the remarkably well-preserved stone ramparts and trace the ancient defensive walls along mountain trails. The site offers panoramic views across the Okayama Plain and toward the Seto Inland Sea, illustrating the castle's strategic importance. The Nishimon Gate ruins remain one of the most photogenic spots, where massive foundation stones reveal the scale of the original entrance.

Several hiking courses wind through the castle grounds, ranging from gentle walks to more challenging climbs through forested sections. The area is particularly atmospheric during spring cherry blossom season and autumn foliage.

Kinojo Castle is accessible by car, located approximately 20 kilometers northwest of Okayama City center. Visitors should drive to the Kinojo Visitor Center parking area, from which trails lead to various castle sections. Public transport options are limited, though buses run from Bitchu-Takamatsu Station on the JR Hakubi Line to nearby stops, requiring additional walking or taxi service. The site is open year-round with no admission fee.