Dunkerque is a wonderful place to visit at this time of year: the winter chill is just about over and the beach is fantastic under the sun and blue sky (although i won't recommend going for a swim: the water is absolutely freezing). The auberge de jeunesse (HI youth hostel) is right around the corner from the beach and within easy reach of the centre of town. the staff there will offer you a warm and friendly reception. plus the picturesque city of Bergues (have you seen 'bienvenue chez les ch'tis'/'welcome to the sticks' yet?)is just down the road and is more than worth a stop on either your way to or from Dunkerque.