Nagoya Castle Ruins & Saga Prefectural Nagoya Castle Museum

Nagoya Castle in Chinzei-cho, Karatsu City, was built in 1591-1592 by Toyotomi Hideyoshi as the staging base for his two invasions of Korea, the Bunroku and Keicho campaigns, and briefly became one of the largest castle towns in Japan, housing daimyo encampments from across the country. The castle was abandoned and largely dismantled in the early Edo period, and today only the stone foundation walls, moats, and terraced baileys remain on the hilltop overlooking the Genkai Sea and nearby Iki Island, giving visitors an unusually open, uncluttered sense of a castle's original scale compared to reconstructed donjons elsewhere in Japan. Climbing through the ruins to the former main bailey takes about 30 to 45 minutes and offers wide sea views in most directions. The adjacent Saga Prefectural Nagoya Castle Museum, built into the hillside below the ruins, focuses on the historical exchange between Japan and Korea across the centuries, displaying excavated artifacts, models reconstructing the former castle town, and exhibits that address the war's impact from both Japanese and Korean historical perspectives. A full visit to the museum and the ruins takes about an hour and a half to two and a half hours combined. The site is quiet most of the year, with weekday mornings offering the emptiest ruins for photography of the stone walls against the sea; the surrounding hillside also gives good visibility toward Nagasaki's Hirado area on clear days.