Sendai Castle (Japanese: 仙台城, Sendai-jō), also known as Aoba Castle (青葉城), is a Japanese hirayamajiro (hilltop-flatland castle) located on Mt. Aoba in Aoba Ward, Sendai City, Miyagi Prefecture (formerly Miyagi District, Mutsu Province). It is also sometimes referred to as Gojōrō. Today, the site is designated as a National Historic Site of Japan.
Construction of the castle began during the Keichō era under Date Masamune, becoming the residence of the Date clan lords and the administrative center of the Sendai Domain for nearly 270 years until the Meiji Restoration, which saw the abolition of domains and castles.
The castle was largely completed under the second lord, Date Tadamune, occupying an area of approximately 20,000 tsubo (~66,000 square meters), reflecting the status of a powerful domain.
Despite being damaged several times by earthquakes, the castle was restored repeatedly and served as the headquarters of the Ōuetsu Reppan Dōmei during the Boshin War. It survived the conflict without being burned. In the Meiji and Taishō periods, the grounds were used by the military, and most structures were dismantled. The Ōtemon gate, Wakiyagura turret, and Tatsumi-mon gate were designated National Treasures (under the old law), but were tragically destroyed in the 1945 air raids on Sendai. Only parts of the Tora-no-mon gate survive, now repurposed as the front gate of the Miyagi Prefectural Governor’s Residence.
Ownership of the Sendai Castle site is now fragmented. The portion managed by Sendai City as Aobayama Park covers only part of the original site. Other areas are owned by Gokoku Shrine and Tohoku University due to prewar land arrangements. Even between the Honmaru (main bailey) and Ninomaru (second bailey), clear property boundaries remain.
The name “Aoba Castle” is still officially used by Miyagi Gokoku Shrine, referring to their location as “Aoba Castle Site.” Sendai City, which manages part of the site, uses the term “Sendai Castle Ruins”, and this was the official name registered when the site was designated as a National Historic Site in 2003. Previously, the name “Sendai Castle Site” was more commonly used, and it still appears on some signage, such as in the Aoba-dōri underground walkway. Thus, multiple names for the same location are still in use today.
Around the San-no-maru (third bailey), near the Sendai City Museum, remnants of moats and stone walls are still visible. From there, a short hike up Mt. Aoba leads to the impressive stone walls of the Honmaru. From the top, visitors can enjoy sweeping views of central Sendai, the Sendai Plain, and, on clear days, even the Pacific Ocean.
The Ninomaru site to the north is now primarily occupied by Tohoku University. However, the eastern part and the northeastern roundabout area are owned by Sendai City as an enclave of Aobayama Park.
There are plans to reconstruct key wooden structures, including the Honmaru Palace, gates, turrets, earthen walls, and the Ōtemon and Wakiyagura, which were lost in wartime air raids or destroyed during the Meiji period.
