I love this museum in Freiburg. It is charming and unexpected. It has a diverse selection of art and I have always enjoyed going there. It is a perfect activity on a rainy day and you will not have to plan a whole day to do so. As others mentioned, it is on the smaller side so if you take your time it may take 2 to 3 hours; if you don't take your time you can easily do it within 2 hours.