The Aachen Cathedral Treasury is a museum of the Roman Catholic Diocese of Aachen under the control of the Cathedral chapter, which houses one of the most important collections of medieval church artworks in Europe. In 1978, the Aachen Cathedral Treasury, along with Aachen Cathedral, was the first monument on German soil to be entered in the List of UNESCO World Heritage Sites. The Treasury contains works from Late Antique, Carolingian, Ottonian, Staufen, and Gothic times.