The Isle of Kerrera sits just across the water from Oban, close enough for an easy outing but far enough to feel like you have left the ferry-port bustle behind. The island has quiet lanes, coastal walking, sheep fields, sea views and the ruins of Gylen Castle near its southern end.
It works well as a half-day or full-day walk, depending on how much of the loop you take on. Check ferry times carefully, bring food if you are travelling outside the main season, and enjoy the way Oban's harbour suddenly looks better from the other side.