If you have a few more days to spare and you’re willing to travel 20 miles, check out Gluecksburg. This happening destination boasts plenty to keep you occupied. Explore the area starting with Flensburg Harbor, Gluecksburg Castle and Solitude Beach. Don’t forget about Flensburg either! Just 25 miles away, Flensburg Harbor, Gluecksburg Castle and Solitude Beach are must-sees here.