From the Middle Ages to modern times, the time travel through the history of the city of Hagen unfolds. The presentation begins in the year 775 – with the first mention of Syburg in the Ruhr Valley near Hagen in the Carolingian imperial annals, bringing the area of Westphalia and the region into the light of written records. Among the objects of the Hagen city history on display in the city museum are, for example, a belt buckle and a chain mail from the Middle Ages, objects from Hagen dynasties such as the Harkort family, as well as evidence of National Socialism in the Volme city.
Over 3000 exhibits have been included in the permanent exhibition. The largest exhibit – the war memorial "Iron Smith" from 1915 – is displayed in the entrance hall. The museum building on Hochstraße was constructed in 1866 for the royal-Prussian city court. Over the decades, the classicist building has undergone various uses – most recently, it served as the administrative headquarters for the department of museums and archives.

Rainer Stamm took over the management at the beginning of September. Thus, the 57-year-old, a native of Hagen, will also direct the Osthaus Museum in the future. Since 2010, the art historian and literary scholar has been the director of the Landesmuseum Kunst & Kultur in Oldenburg. Stamm has also made a name for himself as the editor of the speeches and writings of Karl Ernst Osthaus – in 1902, the patron established the Folkwang Museum in Hagen (which later moved to Essen). In 2022, his biography 'Karl Ernst and Gertrud Osthaus. The Founders of the Folkwang Museum and Their World', co-authored with Gloria Köpnick, was published.
'The Osthaus Museum with its magnificent collections as well as the cultural treasures of our city have always been particularly close to my heart,' said Rainer Stamm. 'With the reopening of the Stadtmuseum, which enriches the museum quarter along with the Emil Schumacher Museum and the Osthaus Museum from mid-month, we have a great museum center.'
