Locals love to hang out at the Kralingse Plas. This is the biggest open air recreation park in Rotterdam with a lake. Therefore perfect for a relaxing picnic or any water activity. Rent a sailboat where you might end up at the naked beach. Also have a walk along the lake and admire the many skaters and runners all year around. Take your little ones to the Fun Forest where they can swing like little monkeys. Here is the location!