The last renovation of the museum took place in the 1970s. Large parts of the exhibition remain unchanged. Numerous showcases still offer a fascinating view of typical local habitats. Such showcases, in which sections of nature are recreated down to the smallest detail, are called dioramas. They offer visitors educational insights into the nature of the Düsseldorf region that they would otherwise never see.
Parts of Dr. Peter Frey's bird collection are also on display in the museum. The dentist from Leverkusen has independently collected over 1,074 birds, stuffed them lifelike and installed them in 450 display cases with a naturalistic background painting - mini or individual dioramas. In doing so, he has created scenes of lasting value. The museum's technical equipment includes a unique bird clock that makes the birds of the castle park sing throughout the day, while the permanent exhibition "How people see animals. The animal sculptures of Josef Pallenberg". The exhibition shows animal sculptures by the internationally renowned animal sculptor Josef Pallenberg (1882-1946). These address in a unique way the tension between artistic and zoological intention, the boundaries between nature and art and reveal a unique animal-human relationship.
