Gassantoda Castle is regarded as among Japan's Five Greatest Mountain Castles, along with Kasugayama Castle, Nanao Castle, Kannonji Castle and Odani Castle. Now it is one of Japan's nationally designated historical ruins.
From 1396 to 1566 it was the seat of the powerful Amago clan and regarded as the most impregnable castle in Japan. In 1566, after several failed assaults and a prolonged siege, it fell to Mōri Motonari. The defeat marked the end of the Amago clan as a force in the region and confirmed Motonari's rise to the position of most powerful warlord in Western Japan.
|Wikimedia Commons has media related to Gassan Toda Castle.|
- Japanese Castle Explorer - Gassan Toda Castle
- 戦国の覇者・尼子盛衰記をめぐる page at official site of city of Yasugi