Niitakayama Castle, Historic mountain castle in Mihara, Japan

Niitakayama Castle is a mountain fortress in Mihara built on a strategic hilltop location. The remaining stone walls and dry moats show how the structure was designed to defend the area.

Kobayakawa Takakage built the fortress in 1552 during the Sengoku period when military power struggled between different lords. The site was dismantled in 1596 when a new castle was constructed nearby.

The castle site was originally the location of Kyoshi-ji, the Kobayakawa clan's family temple, which dated from the Kamakura period. The temple was removed to make room for the castle when Takakage rebuilt the fort in 1552. The mountain-top enclosures carry unusual names such as Shinzōsu-kuruwa and Raigenga-maru.

The site is accessible by a short walk from JR West Hongō Station, making it easy to reach on foot. Wear comfortable shoes as the paths climb uphill and some areas have uneven terrain.

The castle's enclosures carry unusual names such as Shinzōsu-kuruwa and Raigenga-maru, recorded in no other castle of the region. On the summit, the honmaru still shows earthen ramparts in a masugata (right-angle) layout and the foundation stones of buildings. The site was added to the Continued 100 Fine Castles of Japan as number 173 in 2017.