Morioka Castle has no keep left, but the stone walls are impressive: broad granite terraces rising above the meeting of the Kitakami and Nakatsu rivers. The park was laid out in the early 20th century on the former castle grounds and is especially good in cherry-blossom season and autumn.
It is the natural place to start exploring Morioka. The city centre wraps around it, the history museum sits on one edge, and the upper walls still give a clear sense of why the Nanbu clan chose this spot for their stronghold.