Tanasoko Castle

Architecture, patrimoine et histoire · Préfecture de Kumamoto

Clinging to a spur that Mount Kuradake (682 m) sends southward on the island of Kamishima, Tanasoko Castle is one of the richest witnesses to the feudal fragmentation of the Amakusa archipelago. In the Muromachi period, five small lordly houses contended for these islands, and Tanasoko became the prize in the rivalry between the Kōzuura and the Sumoto: held by the former in 1544, it passed to the latter before returning to the Kōzuura in 1560 through the mediation of the Sagara clan. What is striking is the scale of the site: eight enclosures are staggered along some 340 m of ridge, a complex plan unmatched in a region dominated by single-enclosure forts, reinforced by a triple moat to the north and east. Excavations revealed a large building with post holes cut into the rock and remarkable finds — Chinese tenmoku bowls, tea grinding stones, go pieces — evoking a refined tea culture between the late 14th and late 16th centuries. National Historic Site since 2009.