For an offbeat day out, pre-book a place on the former mail boat to the wooded island of Romsø, whose houses still stand though it's been depopulated for decades – residents are now limited to deer, rabbits and birds. The trip takes 30 minutes and you get five hours to explore, perhaps walking the 3km coastal trail or following the boatman's tour.
Bring a picnic lunch as there are no facilities. Trips generally run on Wednesdays and Saturdays from April to August, but in summer there are many extra departure days according to demand so it's worth enquiring. Reservations are essential; 17/four passengers maximum/minimum. Cancelled in severe weather.