月山富田城

Lien avec les sabres

Gassan Toda Castle's sword connections are inseparable from Izumo Province's identity as Japan's 'land of iron.' The Chūgoku Mountains held vast deposits of iron sand (satetsu), fueling the distinctive 'tatara' smelting industry that supplied high-quality tamahagane (sword steel) to smiths across Japan. The Amago clan's control of this iron economy was a pillar of their military power. The castle's very name connects to the celebrated Gassan school of swordsmiths — active since the late Heian period — whose blades are instantly recognizable by their 'ayasugi-hada,' a mesmerizing woodgrain-like surface pattern unique in Japanese swordsmithing. Modern Yasugi City is home to Yasuki Steel (now Proterial), whose specialty steel is used in high-end kitchen knives worldwide — a living legacy of the region's iron heritage stretching from medieval tatara furnaces to global precision manufacturing.