Sendai Castle, Japanese castle in Aoba, Japan

Sendai Castle sits on Mount Aoba, with its honmaru about 115 meters high, a roughly square area 250 meters long enclosed by stone walls up to 15 meters high. The site is protected by cliffs to the south and east and by forest to the west. The honmaru held the foundation for a keep that was never built and was guarded by four three-story yagura.

Date Masamune founded the fortress in 1601 as the administrative center of his domain. It served as the seat of power for 270 years until the Meiji Restoration ended the feudal system and most buildings were dismantled.

The castle is also called Aoba Castle, a name linked to the fresh green of Mount Aoba and to Aoba-san, the mountain name of the Shokō-ji temple that once stood between the inner and second baileys. The honmaru had no keep, only a foundation, and was guarded by four three-story turrets. The daimyō residence, compared to Toyotomi Hideyoshi's Jurakudai, included a 430-tatami great hall and a cliff-hanging viewing pavilion.

A reconstructed guard tower stands today as the only structure on the grounds and offers views across the city to the Pacific. Paths lead through the remaining wall sections and require sturdy footwear because of the uneven stone surfaces.

The honmaru walls use a cut-stone technique called kirikomi-tsumi, with corner stones finished by the Edo-kiri method. Excavation during the 1997–2004 repairs revealed two older walls inside the present one, including an unworked nozura-zumi wall from Masamune's time, showing an earlier collapse caused by an earthquake.