Lothar Franz laid the foundation for one of the largest private collections of old masters in the German-speaking region and this collection still contains many invaluable works. The guided tour takes visitors past works by Breughel, Dürer, van Dyck, Rubens and Tizian. A large collection of furniture, glass and porcelain is also on show. The library compiled by Lothar Franz is still completely preserved in its original state.

Frequent requests for the inclusion of individual works in international exhibitions and countless queries from the scientific field continue to underline the significance of the collection to the present day.