We found Al's Kloster quiet and peaceful. This beautiful bed and breakfast is just outside of Sonderborg (5-10 min), so you do need transportation... but, once you get here it is well worth it! It sits in a beautiful setting and there are trails, right from your door, that you can take down to the water and beyond, along the coast.
The rooms are all different. They are clean and best of all the beds are good... European style with a down quilt as a blanket. Enjoy!