Nanao Castle (Masuda)

Architecture, patrimoine et histoire · Préfecture de Shimane

On a hill about 118 m high overlooking the left bank of the Masuda River, Nanao Castle and the Mitaku-Odoi residence at its foot formed the centre of the Masuda clan, the most powerful warrior family of Iwami Province in the Middle Ages. First mentioned in a document of 1336, the castle was extensively remodelled in 1551 as tension with the Mōri grew. It extends about 400 m east to west and 600 m north to south: more than forty terraces in six sectors frame a small valley through which the access path climbed. Groups of parallel trenches protect the flanks of the main enclosure, and a wet moat ran around the western foot of the hill. Excavations from 1990 to 2001 uncovered buildings on stone foundations, a tile-roofed gate and a small gravel garden, together with abundant ritual tableware showing that the lord lived and held ceremonies there. In 1583 the Masuda left the castle for Mitaku-Odoi, and after 1600 they followed the Mōri to Susa. Designated a National Historic Site in 2004 as the 'Masuda clan castle and residence sites', it is part of the Japan Heritage story devoted to medieval Masuda. The gate of the Ikō-ji temple at its foot is said to come from the castle.