You can take time to visit Priwall Peninsula during your travels to Lübeck. Take in the museums while you're in the area.
You can find out about the history of Gluecksburg with a visit to Gluecksburg Castle. While you're in the area, stroll along the waterfront.
Nothing says vacation like spending a lazy day at Sankt Peter Ording Beach, a popular beach in St. Peter-Ording. While you're in the area, wander around the parks.