The mill was put up on ducal property as a small water mill for the use of the castle's residents. The building is also thought to have a castle granary function because of its considerable size and narrow granary-type windows. The mill construction was first rebuilt in the beginning of the XVI century, later in 1863 and 1880, and finally in the beginning of the XX century. It was used as a mill until 1964 and, four years later – in 1968 – after restoring its previous form from the XVI century, the mill was readopted to house the Department of Ethnography of the Middle Pomerania Museum.

Richter's Granary Primarily, the granary as a three floors' historic half-timbered building stood at the corner of Kopernik and Wolnosci Streets in Slupsk. The Middle Pomerania Museum took over the building in 1986. Because of its bad technical state, the granary was pulled down and removed from in its primary location and then rebuilt on old Fish Market. Attempts to move the granary took almost four years and, in May 1998, it opened its doors for tourists visiting the castle. You can find it now where a tea shop is situated. In the summertime, Jarmark Gryfitow (English: Griffins' Fair) is organised in front of it and, in the wintertime, this is a traditional place for a salmon fishing party on the Slupia River.

Museum pieces that remained after closing Heimatmuseum (1924÷1945) and that were taken over by the Museum in Slupsk in 1965 became a great testimony of Middle Pomerania's history, art and ethnography background. In Castle's museum rooms, concerts, lectures, seminars and museum lessons also take place. Both regular and temporary exhibitions are organised. Currently, regular exhibitions include: “Treasures of Pomeranian dukes”, “Old art of Pomerania, XIV÷XVIII century”, “Stanislaw Ignacy Witkiewicz – Witkacy (1885-1939), plastic arts”– in the castle; ethnographic exhibition “Cultural reality of Pomerania in the past and now”– in the castle mill. Some temporary exhibitions are also organised in Richter's Granary. The manor house is a place where the museum's board, accounts and administration departments have their offices. In Mill Gate, you can find photography and conservator's studios. The Slovincian Countryside Museum in Kluki and Albrecht's Farm in Swolowo are branches of the Middle Pomerania Museum.

Museum of the Middle Pomerania The museum is located in the following restored buildings: