Visited in October 2020
It's essentially a remnant of a feudal castle that is repurposed as a park, which is unique. Typically, Japanese cities and towns just simply let their castle ruins (those that didn't survive intact through the post-feudal and World War 2 eras) to rot. Here, instead of fully restoring the castle or raze it, they preserved the moat, enclosure walls, and guard towers as they are. The inner part of the castle, which is now an empty ground, becomes a public space, where the locals do sports and other recreational activities, and occasionally local festivals.
Surprisingly, elevators were installed to access the wall rampart. The guard towers also house some artifacts of the feudal era, but by the time of my visit, it was off limits and not in display for public.