The "Immengarten" is the museum's attempt to bring some nature into the middle of the city, Lübeck being a city with relatively few parks and large green areas in the center. This garden features loads of wildflowers, an insect hotel and a beehive (the bees also have an indoor beehive inside the museum). The garden is located outside the entrance, so it can be seen for free.
Museum für Natur und Umwelt is the natural history museum of Lübeck, Germany. It's not a very big museum, but it's a nice little place which is worth a visit if you've already done the major sights of the city.
The museum has three floors with various exhibitions: First floor: The geological history of Schleswig-Holstein. Second floor: Various exhibitions on the present-day nature of Schleswig-Holstein, mostly focusing on freshwater and saltwater habitats. Also a few exhibits for live animals. Third floor: More exhibitions on the present-day nature of Schleswig-Holstein, mostly focusing on woods, urban areas, and agriculture. Half of the floor is used for temporary exhibitions.