Nagahama Castle, Castle ruin from Sengoku period in Numazu, Japan

Nagahama Castle is a Sengoku-period castle ruin on a low hill about 30 meters high on the Uchiura coast of Suruga Bay in Numazu, Japan. It consists of terraces following the hill's contour, protected by clay ramparts and dry moats, with cut stone facing only on vulnerable sections. The second bailey, the largest at 665 square meters, has clay walls 3 to 5 meters wide on its south and west sides.

The Late Hojo clan built Nagahama Castle in 1579 to block the route from Suruga Bay to their stronghold at Nirayama, after Takeda Katsuyori raised Miha Castle near the border. In 1580 the Hojo and Takeda navies fought the Suruga Bay sea battle offshore. The castle was abandoned around 1590, when the Hojo surrendered at Odawara.

The path up the hill winds through what were once several gate positions, following a layout designed to slow any attacker down step by step. Walking it today gives a clear sense of how defenders thought about controlling movement through the site.

The paths on the hill are steep and uneven in places, so sturdy shoes make the walk much easier. Visiting during daylight is the best way to navigate the slope safely and take in the views from the top.

The hilltop served as a naval observation point over Uchiura anchorage, not just a land fortress. This combination of land defense and sea surveillance in one site was relatively rare among the strongholds of the region.