Marugame (ŪT) is a port city in western Kagawa Prefecture on Shikoku, located just west of the Seto Ohashi Bridge which connects Shikoku to Japan's main island of Honshu. The second largest city in the prefecture, Marugame includes many of the Shiwaku Islands, a historically important island group that lies just off the coast of the city. The Shiwaku Islands include Honjima Island, the former governing center of the island group. Several of the islands serve as festival venues for the Setouchi Triennale.
For centuries, Marugame's location along the Seto Inland Sea has made it an important player in maritime trade and transportation through the region. Marugame Castle was built high up on a hill overlooking the city as a means to help control the area. The castle is one of only twelve so-called "original castles" in Japan, i.e. castles whose keeps have survived the post-feudal period (since 1868) intact.