Maruoka Castle was built in 1576 by Shibata Katsutoyo, nephew of the famed warrior Shibata Katsuie. Ownership of the castle changed hands numerous times before Honda Narishige was installed in 1613 and made major improvements, resulting in the design we see today. It was long believed that Maruoka’s tenshu tower keep was the oldest remaining, however recent research has shown that the timbers were cut in the late 1620s. The tenshu itself is relatively small and simple, having two levels with three floors in the typical boro-gata style, being of similar construction to a temple, but having extra floors and a watchtower on top. The roofing tiles are carved from local stone, making it rather heavy, hence the many support pillars inside the small tenshu. The first floor of the structure was built slightly in from the edge of the stone wall base, and so angled protective covers surround the tenshu base. The castle layout was originally pentagonal in shape, however, most of the outer sections and moats have since been covered over and built upon.