The Diocesan Museum is one of the most prominent museums in the German city of Osnabrück. The museum is located inside the Roman monastery of St. Peter's Basilica. displays a valuable collection of various exhibits relating to the history of the Osnabrück diocese from the Cathedral Treasury; Which dates back to the period between the eleventh century and the eighteenth century, and includes many paintings, sculptures, textiles, costumes and other belongings of saints.