The local highlights are spread out (Schloss Gottorf is 1.5km from the train station; the old town and cathedral are another 2km east of there). With your own transport you can see everything in half a day, otherwise, plan on spending the day exploring.

Spend some time wandering the cobblestoned streets around the Rathhausmarkt. The traditional fishing village of Holm is 500m southeast along the waterfront.