Marugame is a hilltop castle with a rinkakushiki layout. In the pre-modern age, it lay within the borders of Sanuki Province. It was in use from 1597 to 1871. Its position near the narrowest part of the Seto Inland Sea enabled it to control this most important route in Japan.

From the elevated tracks of JR Marugame Station, Marugame Castle presents a slightly odd appearance — a small tower perched atop massive stone fortifications. This is because the walls were built for a grander edifice. Marugame Castle was originally constructed between 1597 to 1602 by Ikoma Chikamasa, the feudal lord who also built Tamamo Castle in Takamatsu. But due to a new shogunal ruling that limited the number of castles in each province to one, Marugame Castle was dismantled 13 years after its completion. The castle was rebuilt in 1664 by Yamazaki Ieharu after the province had been divided in two, and most of what stands today dates from his reconstruction. Some of the stones in the walls are marked with symbols indicating which vassals provided them.

Besides the stone walls, few of the buildings at Marugame Castle still stand today, though the Ote Ichino Gate, Ote Nino Gate, and the tenshu, which underwent a major restoration in 1950, still stand.