Kristel and Frans guesthouse is absolutely great. We had a wonderful stay at Rotterdam. The Guesthouse has a beautiful terrace/ outdoor space on which you can spend a lovely time when it is good weather or bad. The guesthouse was clean and has everything you need for a comfortable stay. It is nicely done up and you feel very welcomed due to their hospitality. I personally loved the rain shower ;) The guesthouse is nearby a Lidl and is located at the water. It is a little private space in this beautiful city which center you can easily reach by tram.