Perhaps better known as Sendai-jō, Aoba Castle was the center of Date Masamune's capital and power base in Sendai. Set high atop Aoba-yama on the southwestern edge of the city center, the castle was considered virtually impregnable. In fact, Masamune was so confident of its security that he never built a central tenshu (donjon). While the Meiji era unsurprisingly saw some of it dismantled, much of the castle survived into modern times, only to be obliterated by American bombing in World War II. The pictured Sumi-yagura (watchtower) was reconstructed in the 1960s and is the only significant structure left of the castle, other than the magnificent walls, which were recently restored to their original imposing size.