Minato Castle, Fortress ruins in Tsuchizaki Minato, Japan

Minato Castle was a flatland castle (hirajiro) in Tsuchizaki Minato, now part of Akita City. It stood on the site of the present Tsuchizaki Shinmeisha shrine, surrounded by a double water moat, and was demolished in 1604. Excavations in 2005–2008 uncovered its moat and remains from the Azuchi–Momoyama period.

The castle was built around 1436 by Ando Yasusue as the headquarters of the Ando clan, who controlled much of northern Japan's coastal trade at the time. In 1602, control of the region passed to the Satake family following political changes in the country.

The name Minato means "harbor", matching the port district of Tsuchizaki Minato where the castle stood. After its demolition in 1604, the flat site was largely built over with townsmen's houses, and this became the base for the prosperity of the port town in the Edo period. The Tsuchizaki Shinmeisha shrine was built on the grounds in 1620.

The site is easy to reach on foot from Tsuchizaki Station, and information panels placed around the grounds help visitors understand what they are looking at. Clear weather makes the visit more rewarding, as the view over the coast opens up from the hilltop.

Minato Castle was a flat castle (hirajiro) ringed by a double water moat, not a hilltop fort. After Satake Yoshinobu abandoned it in 1604, most of the land became townsmen's residences, laying the base for the prosperity of the port town of Tsuchizaki Minato in the Edo period.