Kesennuma Oshima is the island in the mouth of Kesennuma Bay, reached by bridge since 2019. It is small enough to explore by bicycle or on foot, with coves, fishing hamlets, Odanohama Beach, and viewpoints along the coastal loop.
The island gives Kesennuma a gentler side after the museums and port. Come for a half day if the weather is clear, or make it a full day if you want to walk a longer section of the Michinoku Coastal Trail.